Fair Value Measurements Not Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2016		Dec. 31, 2015	Mar. 31, 2015	[2]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	$ 112,861		$ 116,384
Federal funds purchased	40,000		0
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	2,428	[1]		$ 757
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	0	[1]		0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	0	[1]		0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	2,428	[1]		$ 757
Reported Value Measurement, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	113,946		238,694
Held-to-maturity Securities, Fair Value	111,337		116,352
Loans Held-for-sale, Fair Value Disclosure	5,383		8,072
Loans Receivable, Fair Value Disclosure	5,581,754		5,640,712
Other Assets, Fair Value Disclosure	116,982		118,233
Deposits, Fair Value Disclosure	5,786,860		6,040,437
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	63,182		58,215
Federal funds purchased	40,000
Federal Home Loan Bank Borrowings, Fair Value Disclosure	523,952		461,324
Subordinated Debt Obligations, Fair Value Disclosure	106,363		106,363
Other Liabilities, Fair Value Disclosure	2,013		1,978
Portion at Fair Value Measurement, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	113,946		238,694
Held-to-maturity Securities, Fair Value	112,861		116,384
Loans Held-for-sale, Fair Value Disclosure	5,490		8,144
Loans Receivable, Fair Value Disclosure	5,643,839		5,658,254
Other Assets, Fair Value Disclosure	116,982		118,233
Deposits, Fair Value Disclosure	5,788,934		6,041,239
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	63,182		58,215
Federal funds purchased	40,000
Federal Home Loan Bank Borrowings, Fair Value Disclosure	529,789		465,100
Subordinated Debt Obligations, Fair Value Disclosure	96,363		96,363
Other Liabilities, Fair Value Disclosure	2,013		1,978
Portion at Fair Value Measurement, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	113,946		238,694
Held-to-maturity Securities, Fair Value	0		0
Loans Held-for-sale, Fair Value Disclosure	0		0
Loans Receivable, Fair Value Disclosure	0		0
Other Assets, Fair Value Disclosure	0		0
Deposits, Fair Value Disclosure	0		0
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	0		0
Federal funds purchased	0
Federal Home Loan Bank Borrowings, Fair Value Disclosure	0		0
Subordinated Debt Obligations, Fair Value Disclosure	0		0
Other Liabilities, Fair Value Disclosure	0		0
Portion at Fair Value Measurement, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0		0
Held-to-maturity Securities, Fair Value	112,861		116,384
Loans Held-for-sale, Fair Value Disclosure	5,490		8,144
Loans Receivable, Fair Value Disclosure	0		0
Other Assets, Fair Value Disclosure	116,982		118,233
Deposits, Fair Value Disclosure	5,788,934		6,041,239
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	63,182		58,215
Federal funds purchased	40,000
Federal Home Loan Bank Borrowings, Fair Value Disclosure	529,789		465,100
Subordinated Debt Obligations, Fair Value Disclosure	0		0
Other Liabilities, Fair Value Disclosure	2,013		1,978
Portion at Fair Value Measurement, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0		0
Held-to-maturity Securities, Fair Value	0		0
Loans Held-for-sale, Fair Value Disclosure	0		0
Loans Receivable, Fair Value Disclosure	5,643,839		5,658,254
Other Assets, Fair Value Disclosure	0		0
Deposits, Fair Value Disclosure	0		0
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	0		0
Federal funds purchased	0
Federal Home Loan Bank Borrowings, Fair Value Disclosure	0		0
Subordinated Debt Obligations, Fair Value Disclosure	96,363		96,363
Other Liabilities, Fair Value Disclosure	$ 0		$ 0

[1] Collateral-dependent impaired loans held at March 31, 2016 that had write-downs in fair value or whose specific reserve changed during the first three months of 2016.

[2] Collateral-dependent impaired loans held at March 31, 2015 that had write-downs in fair value or whose specific reserve changed during the first three months of 2015.