| **Investment Securities (Tables)**                                 | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
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| **Investments, Debt and Equity Securities [Abstract]**             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| Schedule of Available-for-sale Securities Reconciliation           | The following table summarizes the amortized cost and estimated fair value of investment securities and presents the related gross unrealized gains and losses:June 30, 2014        (dollars in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair ValueAvailable-for-Sale:        Obligations of:        U.S. government sponsored enterprises $2,040 $24 $— $2,064Residential mortgage-backed securities-GSE 347,916 1,278 12,298 336,896Residential mortgage-backed securities-Private 18,404 1,104 — 19,508Commercial mortgage-backed securities-GSE 22,573 — 522 22,051Commercial mortgage-backed securities-Private 10,387 — 241 10,146Corporate notes 8,395 50 — 8,445Total available-for-sale $409,715 $2,456 $13,061 $399,110Held-to-Maturity:        Residential mortgage-backed securities-GSE 136,987 — 4,589 132,398Commercial mortgage-backed securities-Private 10,068 — 178 9,890     Total held-to-maturity $147,055 $— $4,767 $142,288Total investment securities $556,770 $2,456 $17,828 $541,398         December 31, 2013        (dollars in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair ValueAvailable-for-Sale:        Obligations of:        U.S. government sponsored enterprises $2,051 $26 $— $2,077Residential mortgage-backed securities-GSE 364,513 974 24,340 341,147Residential mortgage-backed securities-Private 19,770 982 — 20,752Commercial mortgage-backed securities-GSE 22,767 — 1,328 21,439Commercial mortgage-backed securities-Private 10,408 — 823 9,585Business Development Company investment 1,753 984   2,737Corporate notes 16,795 82 — 16,877Total available-for-sale $438,057 $3,048 $26,491 $414,614Held-to-Maturity:        Residential mortgage-backed securities-GSE 141,724 — 9,907 131,817Commercial mortgage-backed securities-Private 10,071 — 763 9,308     Total held-to-maturity $151,795 $— $10,670 $141,125Total investment securities $589,852 $3,048 $37,161 $555,739 |
| Available-for-sale Securities, Continuous Unrealized Loss Position | The following tables show our investments' estimated fair value and gross unrealized losses, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position, at June 30, 2014 and December 31, 2013.  The change in unrealized losses during the six months ending June 30, 2014 was attributed to changes in interest rates and not to changes in the credit quality of these securities. All unrealized losses on investment securities are considered by management to be temporary given the credit quality of these investment securities or the short duration of the unrealized loss, or both. Less than 12 Months 12 Months or More Total(dollars in thousands)Estimated Fair ValueGross Unrealized Losses Estimated Fair ValueGross Unrealized Losses Estimated Fair ValueGross Unrealized LossesJune 30, 2014        Available-for-Sale:        Residential mortgage-backed securities-GSE$14$— $300,334$12,298 $300,348$12,298Commercial mortgage-backed securities-GSE—— 22,052522 22,052522Commercial mortgage-backed securities-Private—— 10,146241 10,146241Total available-for-sale$14$— $332,532$13,061 $332,546$13,061Held-to-Maturity:        Residential mortgage-backed securities-GSE$—$— $132,398$4,589 $132,398$4,589Commercial mortgage-backed securities-Private—— 9,890178 9,890178Total held-to-maturity$—$— $142,288$4,767 $142,288$4,767Total$14$— $474,820$17,828 $474,834$17,828         December 31, 2013        Available-for-Sale        Residential mortgage-backed securities-GSE$222,475$16,585 $76,501$7,755 $298,976$24,340Commercial mortgage-backed securities-GSE—— 21,4391,328 21,4391,328Commercial mortgage-backed securities-Private9,585823 —— 9,585823Total available-for-sale$232,060$17,408 $97,940$9,083 $330,000$26,491Held-to-Maturity:        Residential mortgage-backed securities-GSE$131,817$9,907 $—$— $131,817$9,907Commercial mortgage-backed securities-Private9,308763 —— 9,308763Total held-to-maturity$141,125$10,670 $—$— $141,125$10,670Total$373,185$28,078 $97,940$9,083$471,125$37,161                                                                                                                                                                                                                                                                                                        |
| Available-for-sale Securities, by Maturity Dates                   | The aggregate amortized cost and fair value of securities at June 30, 2014, by remaining contractual maturity, are shown in the following table.  Actual expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations.  Available-for-Sale Held-to-Maturity(dollars in thousands) Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair ValueDue in one year or less $8,395 $8,445 $— $—Due after one year through five years 2,040 2,064 — —Total 10,435 10,509 — —Mortgage-backed securities 399,280 388,601 147,055 142,288Total $409,715 $399,110 $147,055 $142,288                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |

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Tabular disclosure of fair value of investments in debt and equity securities in an unrealized loss position categorized neither as held-to-maturity nor trading securities.
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Tabular disclosure of maturities of an entity's investments as well as any other information pertinent to the investments.
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No definition available.
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