| **Retirement Plans (Tables)**                                                             | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
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| **Compensation and Retirement Disclosure [Abstract]**                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| Schedule of Components of Net Periodic Benefit Cost                                       | Net periodic benefit cost of these plans for the years ended December 31, was as follows: 2013 2012 2011 (dollars in thousands)Service cost$— $— $—Interest cost on projected benefit obligation62 75 86Amortization of transition obligation— 2 2Gain amortization(7) (32) (50)Net periodic benefit cost$55 $45 $38                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| Schedule of Changes in Benefit Obligations and Plan Assets                                | The following table sets forth the change in the benefit obligation and plan assets as of December 31: 2013 2012 (dollars in thousands)Change in Benefit Obligation   Benefit obligation at beginning of year$1,986 $1,892Service cost— —Interest cost62 75Amendments— —Actuarial (gain) loss(225) 269Net benefits paid(179) (250)Benefit obligation at end of year1,644 1,986Change in Plan Assets   Fair value of plan assets at beginning of year— —Actual return on plan assets— —Employer contributions179 250Net benefits paid(179) (250)Fair value of plan assets at end of year— —Funded Status at End of Year1,644 1,986Unrecognized transition obligation— —Unrecognized net gain430 212Amounts recognized in retained earnings$2,074 $2,198                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| Schedule of Amounts Recognized as Other Liabilities                                       | As of December 31, the funded status of the plan is: 2013 2012 (dollars in thousands)Amounts Recognized in the Statement of Financial Condition as Other liabilities$1,644 $1,986                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| Schedule of Amounts Recognized in Accumulated Other Comprehensive Income                  | The following table identifies the related tax effects allocated to each component of other comprehensive income in the Consolidated Statements of  Comprehensive Income as of December 31. Reclassification adjustments related to securities available for sale are included in the "Net securities gains" line in the Consolidated Statements of Income.  The non-credit related (losses) gains on securities not expected to be sold are included in the "Noninterest Income" section of the Consolidated Statements of Income. 2013 2012 2011 Pretax Amount Tax (Expense) Benefit Net of Tax Amount Pretax Amount Tax (Expense) Benefit Net of Tax Amount Pretax Amount Tax (Expense) Benefit Net of Tax Amount (dollars in thousands)Unrealized gains (losses) on securities:                 Unrealized holding (losses) gains on securities arising during the period$(44,767) $15,660 $(29,107) $(2,854) $1,006 $(1,848) $9,727 $(3,404) $6,323Non-credit related gains (losses) on securities not expected to be sold9,792 (3,427) 6,365 2,193 (768) 1,425 (425) 149 (276)Reclassification adjustment for losses (gains) on securities included in net income1,158 (405) 753 (192) 67 (125) (2,185) 765 (1,420)Total unrealized (losses) gains on securities(33,817) 11,828 (21,989) (853) 305 (548) 7,117 (2,490) 4,627Unrealized gains (losses) for postretirement obligations:                 Transition obligation— — — 2 (1) 1 2 (1) 1Net gain (loss)219 (77) 142 (300) 105 (195) (260) 91 (169)Total unrealized gains (losses) for postretirement obligations219 (77) 142 (298) 104 (194) (258) 90 (168)Total other comprehensive (loss) income$(33,598) $11,751 $(21,847) $(1,151) $409 $(742) $6,859 $(2,400) $4,459The following table sets forth the amounts recognized in accumulated other comprehensive income that have not yet been recognized as components of net periodic benefit costs as of December 31: 2013 2012 2011 (dollars in thousands)Amounts recognized in accumulated other comprehensive income, net of tax:     Net (gain) loss$(280) $(138) $(333)Transition obligation— — 1Total$(280) $(138) $(332) |
| Schedule of Weighted-Average Assumptions Used to Determine Benefit Obligation             | Weighted-average assumptions used to determine the benefit obligation as of December 31 are as follows: 2013 2012 2011Weighted-average Assumptions     Discount rate4.01% 3.31% 4.22%Health care cost trend: Initial6.75% 7.00% 8.00%Health care cost trend: Ultimate4.75% 4.75% 4.75%Year ultimate reached2022 2022 2016                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| Schedule of Weighted-Average Assumptions Used to Determine Net Periodic Cost              | Weighted-average assumptions used to determine the benefit obligation as of December 31 are as follows: 2013 2012 2011Weighted-average Assumptions     Discount rate4.01% 3.31% 4.22%Health care cost trend: Initial6.75% 7.00% 8.00%Health care cost trend: Ultimate4.75% 4.75% 4.75%Year ultimate reached2022 2022 2016Weighted-average assumptions used to determine the net benefit costs as of December 31 are as follows:  2013 2012 2011Weighted Average Assumptions for Net Periodic Cost     Discount rate3.31% 4.22% 4.71%Health care cost trend: Initial7.00% 8.00% 9.00%Health care cost trend: Ultimate4.75% 4.75% 4.75%Year ultimate reached2022 2016 2016Corridor10.00% 10.00% 10.00%Recognition period for gains and losses11.0 12.0 12.7                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| Schedule of Impact of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates | The health care cost trend rate assumption can have a significant impact on the amounts reported for this plan. A one-percentage-point change in assumed health care cost trend rates would have the following effects: One-Percentage-Point Increase One-Percentage-Point Decrease (dollars in thousands)Effect on postretirement benefit obligation$43 $(39)Effect on total of service and interest cost components2 (2)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| Schedule of Projected Benefit Payments                                                    | As of December 31, 2013, the projected benefit payments for the next ten years are as follows:  Projected Benefit        Payments          (dollars in thousands)2014$19820151932016187201718120181632019 - 2023564                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| Schedule of Amounts Recognized in Accumulated Other Comprehensive Income                  | The estimated costs that will be amortized from accumulated other comprehensive income into net periodic cost for 2014 are as follows (dollars in thousands): PostretirementBenefits (dollars in thousands)Net gain$(29)Transition obligation—Total$(29)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |

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| - Definition
Tabular disclosure of the amounts that are recognized in the balance sheet (or statement of financial position) for pension plans and/or other employee benefit plans, showing separately the assets and current and noncurrent liabilities (if applicable) recognized.
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Tabular disclosure of the net gain (loss) and net prior service cost or credit recognized in other comprehensive income (loss) for the period for pension plans and/or other employee benefit plans, and reclassification adjustments of other comprehensive income (loss) for the period, as those amounts, including amortization of the net transition asset or obligation, are recognized as components of net periodic benefit cost.
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| - Definition
Tabular disclosure of the change in the benefit obligation of pension plans and/or other employee benefit plans from the beginning to the end of the period, showing separately, if applicable, the effects of the following: service cost, interest cost, contributions by plan participants, actuarial gains and losses, foreign currency exchange rate changes, benefits paid, plan amendments, business combinations, divestitures, curtailments, settlements, and special and contractual termination benefits.
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| - Definition
Tabular disclosure of the effect of a one-percentage-point increase and the effect of a one-percentage-point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs and the accumulated postretirement benefit obligation for health care benefits.
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Tabular disclosure of benefits expected to be paid by pension plans and/or other employee benefit plans in each of the next five fiscal years and in the aggregate for the five fiscal years thereafter.
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| - Definition
Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments.
+ References
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