Fair Value Measurements Not Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2016		Dec. 31, 2015	Jun. 30, 2015	[2]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	$ 107,389		$ 116,384
Deposits Held for sale	110,558		0
Federal funds purchased	180,000		0
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	7,806	[1]		$ 1,448
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	7,806	[1]		$ 1,448
Reported Value Measurement, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	126,167		238,694
Held-to-maturity Securities, Fair Value	105,297		116,352
Loans Held-for-sale, Fair Value Disclosure	4,677		8,072
Loans Receivable, Fair Value Disclosure	5,675,744		5,640,712
Other Assets, Fair Value Disclosure	126,796		118,233
Deposits, Fair Value Disclosure	5,536,092		6,040,437
Deposits Held for sale	110,558
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	43,304		58,215
Federal funds purchased	180,000
Federal Home Loan Bank Borrowings, Fair Value Disclosure	678,012		461,324
Subordinated Debt Obligations, Fair Value Disclosure	106,363		106,363
Other Liabilities, Fair Value Disclosure	1,950		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	126,167		238,694
Held-to-maturity Securities, Fair Value	107,389		116,384
Loans Held-for-sale, Fair Value Disclosure	5,549		8,144
Loans Receivable, Fair Value Disclosure	5,757,824		5,658,254
Other Assets, Fair Value Disclosure	126,796		118,233
Deposits, Fair Value Disclosure	5,538,277		6,041,239
Deposits Held for sale	113,679
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	43,304		58,215
Federal funds purchased	180,000
Federal Home Loan Bank Borrowings, Fair Value Disclosure	683,717		465,100
Subordinated Debt Obligations, Fair Value Disclosure	96,363		96,363
Other Liabilities, Fair Value Disclosure	1,950		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	126,167		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
Deposits Held for sale	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	107,389		116,384
Loans Held-for-sale, Fair Value Disclosure	5,549		8,144
Loans Receivable, Fair Value Disclosure	0		0
Other Assets, Fair Value Disclosure	126,796		118,233
Deposits, Fair Value Disclosure	5,538,277		6,041,239
Deposits Held for sale	113,679
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	43,304		58,215
Federal funds purchased	180,000
Federal Home Loan Bank Borrowings, Fair Value Disclosure	683,717		465,100
Subordinated Debt Obligations, Fair Value Disclosure	0		0
Other Liabilities, Fair Value Disclosure	1,950		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	5,757,824		5,658,254
Other Assets, Fair Value Disclosure	0		0
Deposits, Fair Value Disclosure	0		0
Deposits Held for sale	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 June 30, 2016 that had write-downs in fair value or whose specific reserve changed during the first six months of 2016.

[2] Collateral-dependent impaired loans held at June 30, 2015 that had write-downs in fair value or whose specific reserve changed during the first six months of 2015.