| **Loans and Allowance - Allowance for Credit Losses and Loan Portfolio by Loan Segment (Details) - USD ($) $ in Thousands** | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 |
|-----------------------------------------------------------------------------------------------------------------------------|---------------|---------------|---------------|---------------|
| **Financing Receivable, Allowance for Credit Losses [Line Items]**                                                          |          |          |          |          |
| Allowance balances - Individually evaluated for impairment                                                                  | $ 888         | $ 1,689       |          |          |
| Allowance balances - Collectively evaluated for impairment                                                                  | 65,149        | 60,611        |          |          |
| Allowance balances - Loans Acquired with Deteriorated Credit Quality                                                        |               | 153           |          |          |
| Total Allowance for Loan Losses                                                                                             | 66,037        | 62,453        | $ 63,964      | $ 67,870      |
| Loan balances - Individually evaluated for impairment                                                                       | 30,579        | 28,567        |          |          |
| Loan balances - Collectively evaluated for impairment                                                                       | 5,065,844     | 4,595,698     |          |          |
| Loans                                                                                                                       | 5,139,645     | 4,693,822     |          |          |
| Loans acquired with deteriorated credit quality                                                                             |          |          |          |          |
| **Financing Receivable, Allowance for Credit Losses [Line Items]**                                                          |          |          |          |          |
| Loan balances - Loans Acquired with Deteriorated Credit Quality                                                             | 43,222        | 69,557        |          |          |
| Commercial                                                                                                                  |          |          |          |          |
| **Financing Receivable, Allowance for Credit Losses [Line Items]**                                                          |          |          |          |          |
| Allowance balances - Individually evaluated for impairment                                                                  | 37            | 1,277         |          |          |
| Allowance balances - Collectively evaluated for impairment                                                                  | 27,659        | 25,201        |          |          |
| Allowance balances - Loans Acquired with Deteriorated Credit Quality                                                        |               |               |          |          |
| Total Allowance for Loan Losses                                                                                             | 27,696        | 26,478        | 28,824        | 27,176        |
| Loan balances - Individually evaluated for impairment                                                                       | 4,762         | 7,877         |          |          |
| Loan balances - Collectively evaluated for impairment                                                                       | 1,520,981     | 1,298,988     |          |          |
| Loans                                                                                                                       | 1,532,396     | 1,314,174     |          |          |
| Commercial | Loans acquired with deteriorated credit quality                                                                |          |          |          |          |
| **Financing Receivable, Allowance for Credit Losses [Line Items]**                                                          |          |          |          |          |
| Loan balances - Loans Acquired with Deteriorated Credit Quality                                                             | 6,653         | 7,309         |          |          |
| Commercial Real Estate                                                                                                      |          |          |          |          |
| **Financing Receivable, Allowance for Credit Losses [Line Items]**                                                          |          |          |          |          |
| Allowance balances - Individually evaluated for impairment                                                                  | 553           | 243           |          |          |
| Allowance balances - Collectively evaluated for impairment                                                                  | 23,108        | 21,753        |          |          |
| Allowance balances - Loans Acquired with Deteriorated Credit Quality                                                        |               | 149           |          |          |
| Total Allowance for Loan Losses                                                                                             | 23,661        | 22,145        | 19,327        | 23,102        |
| Loan balances - Individually evaluated for impairment                                                                       | 21,358        | 16,670        |          |          |
| Loan balances - Collectively evaluated for impairment                                                                       | 2,315,686     | 2,096,089     |          |          |
| Loans                                                                                                                       | 2,371,765     | 2,169,625     |          |          |
| Commercial Real Estate | Loans acquired with deteriorated credit quality                                                    |          |          |          |          |
| **Financing Receivable, Allowance for Credit Losses [Line Items]**                                                          |          |          |          |          |
| Loan balances - Loans Acquired with Deteriorated Credit Quality                                                             | 34,721        | 56,866        |          |          |
| Consumer                                                                                                                    |          |          |          |          |
| **Financing Receivable, Allowance for Credit Losses [Line Items]**                                                          |          |          |          |          |
| Allowance balances - Individually evaluated for impairment                                                                  |               |               |          |          |
| Allowance balances - Collectively evaluated for impairment                                                                  | 2,923         | 2,689         |          |          |
| Allowance balances - Loans Acquired with Deteriorated Credit Quality                                                        |               |               |          |          |
| Total Allowance for Loan Losses                                                                                             | 2,923         | 2,689         | 2,658         | 2,515         |
| Loan balances - Individually evaluated for impairment                                                                       | 9             |               |          |          |
| Loan balances - Collectively evaluated for impairment                                                                       | 77,470        | 74,717        |          |          |
| Loans                                                                                                                       | 77,479        | 74,717        |          |          |
| Consumer | Loans acquired with deteriorated credit quality                                                                  |          |          |          |          |
| **Financing Receivable, Allowance for Credit Losses [Line Items]**                                                          |          |          |          |          |
| Loan balances - Loans Acquired with Deteriorated Credit Quality                                                             |               |               |          |          |
| Residential                                                                                                                 |          |          |          |          |
| **Financing Receivable, Allowance for Credit Losses [Line Items]**                                                          |          |          |          |          |
| Allowance balances - Individually evaluated for impairment                                                                  | 298           | 169           |          |          |
| Allowance balances - Collectively evaluated for impairment                                                                  | 11,457        | 10,966        |          |          |
| Allowance balances - Loans Acquired with Deteriorated Credit Quality                                                        |               | 4             |          |          |
| Total Allowance for Loan Losses                                                                                             | 11,755        | 11,139        | 13,152        | 15,077        |
| Loan balances - Individually evaluated for impairment                                                                       | 4,450         | 4,020         |          |          |
| Loan balances - Collectively evaluated for impairment                                                                       | 1,151,396     | 1,125,316     |          |          |
| Loans                                                                                                                       | 1,157,694     | 1,134,718     |          |          |
| Residential | Loans acquired with deteriorated credit quality                                                               |          |          |          |          |
| **Financing Receivable, Allowance for Credit Losses [Line Items]**                                                          |          |          |          |          |
| Loan balances - Loans Acquired with Deteriorated Credit Quality                                                             | 1,848         | 5,382         |          |          |
| Finance Leases                                                                                                              |          |          |          |          |
| **Financing Receivable, Allowance for Credit Losses [Line Items]**                                                          |          |          |          |          |
| Allowance balances - Individually evaluated for impairment                                                                  |               |               |          |          |
| Allowance balances - Collectively evaluated for impairment                                                                  | 2             | 2             |          |          |
| Allowance balances - Loans Acquired with Deteriorated Credit Quality                                                        |               |               |          |          |
| Total Allowance for Loan Losses                                                                                             | 2             | 2             | $ 3           |               |
| Loan balances - Individually evaluated for impairment                                                                       |               |               |          |          |
| Loan balances - Collectively evaluated for impairment                                                                       | 311           | 588           |          |          |
| Loans                                                                                                                       | 311           | 588           |          |          |
| Finance Leases | Loans acquired with deteriorated credit quality                                                            |          |          |          |          |
| **Financing Receivable, Allowance for Credit Losses [Line Items]**                                                          |          |          |          |          |
| Loan balances - Loans Acquired with Deteriorated Credit Quality                                                             |               |               |          |          |

| X                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Loans and Leases Receivable
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| - Definition
A valuation allowance for financing receivables that are expected to be uncollectible.
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.
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| - Definition
Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.
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| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
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| - Definition
The balance of financing receivables that were collectively evaluated for impairment.
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The balance of financing receivables that were individually evaluated for impairment.
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Net amount of the investment in a contractual right to receive money on demand or on fixed or determinable dates that is recognized as an asset in the creditor's statement of financial position. Examples include, but are not limited to, credit card receivables, notes receivable and receivables relating to lessor's rights to payments from leases other than operating leases that have been recorded as assets. Excludes trade accounts receivable with contractual maturity of one year or less and arose from the sale of goods or services.
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