Fair Value Measurements Not Measured at Fair Value on a Recurring Basis (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2013 Carrying (Reported) Amount, Fair Value Disclosure [Member]	Mar. 31, 2014 Portion at Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2013 Portion at Fair Value, Fair Value Disclosure [Member]	Mar. 31, 2014 Fair Value, Inputs, Level 1 [Member] Portion at Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2013 Fair Value, Inputs, Level 1 [Member] Portion at Fair Value, Fair Value Disclosure [Member]	Mar. 31, 2014 Fair Value, Inputs, Level 2 [Member] Portion at Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2013 Fair Value, Inputs, Level 2 [Member] Portion at Fair Value, Fair Value Disclosure [Member]	Mar. 31, 2014 Fair Value, Inputs, Level 3 [Member] Portion at Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2013 Fair Value, Inputs, Level 3 [Member] Portion at Fair Value, Fair Value Disclosure [Member]	Mar. 31, 2014 Fair Value, Measurements, Nonrecurring [Member]		Mar. 31, 2013 Fair Value, Measurements, Nonrecurring [Member]		Mar. 31, 2014 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 1 [Member]		Mar. 31, 2013 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 1 [Member]		Mar. 31, 2014 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]		Mar. 31, 2013 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]		Mar. 31, 2014 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member]		Mar. 31, 2013 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure			$ 398,687	$ 191,881	$ 398,687	$ 191,881	$ 398,687	$ 191,881	$ 0	$ 0	$ 0	$ 0
Held-to-maturity Securities, Fair Value	127,719	110,917	127,938	112,014	127,719	110,917	0	0	127,719	110,917	0	0
Loans Receivable, Fair Value Disclosure			5,085,865	5,036,088	5,025,835	4,985,555	0	0	0	0	5,025,835	4,985,555	803	[1]	4,494	[2]	0	[1]	0	[2]	0	[1]	0	[2]	803	[1]	4,494	[2]
Loans Held-for-sale, Fair Value Disclosure			2,297	6,123	2,334	6,130	0	0	2,334	6,130	0	0
Other Assets, Fair Value Disclosure			116,247	117,840	116,247	117,840	0	0	116,247	117,840	0	0
Deposits, Fair Value Disclosure			5,341,644	5,110,370	5,345,117	5,113,224	0	0	5,345,117	5,113,224	0	0
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure			93,550	102,353	93,540	102,343	0	0	93,540	102,343	0	0
Federal funds purchased	15,000	0	15,000		15,000		0		15,000		0
Federal Home Loan Bank Borrowings, Fair Value Disclosure			394,458	367,254	404,148	377,384	0	0	404,148	377,384	0	0
Subordinated Debt Obligations, Fair Value Disclosure			106,363	106,363	96,363	96,363	0	0	0	0	96,363	96,363
Other Liabilities, Fair Value Disclosure			$ 10,252	$ 9,789	$ 10,252	$ 9,789	$ 0	$ 0	$ 10,252	$ 9,789	$ 0	$ 0

[1] Collateral-dependent impaired loan held at March 31, 2014 that had write-downs in fair value or whose specific reserve changed during the first three months of 2014.

[2] Collateral-dependent impaired loans held at March 31, 2013 that had write-downs in fair value or whose specific reserve changed during the first three months of 2013.