Fair Value Measurements Not Measured at Fair Value on a Recurring Basis (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2011 Carrying (Reported) Amount, Fair Value Disclosure [Member]	Sep. 30, 2012 Portion at Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2011 Portion at Fair Value, Fair Value Disclosure [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 1 [Member] Portion at Fair Value, Fair Value Disclosure [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 2 [Member] Portion at Fair Value, Fair Value Disclosure [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Portion at Fair Value, Fair Value Disclosure [Member]	Sep. 30, 2012 Fair Value, Measurements, Nonrecurring [Member]		Sep. 30, 2011 Fair Value, Measurements, Nonrecurring [Member]		Sep. 30, 2012 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 1 [Member]		Sep. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 1 [Member]		Sep. 30, 2012 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]		Sep. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]		Sep. 30, 2012 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member]		Sep. 30, 2011 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			$ 83,585	$ 203,354	$ 83,585	$ 203,354	$ 83,585	$ 0	$ 0
Loans Receivable, Fair Value Disclosure			4,876,478	4,555,114	4,951,667	4,619,821	0	0	4,951,667	20,230	[1]	18,297	[2]	0	[1]	0	[2]	0	[1]	0	[2]	20,230	[1]	18,297	[2]
Loans Held-for-sale, Fair Value Disclosure			135,169	12,069	136,856	12,069	0	136,856	0
Other Assets, Fair Value Disclosure			121,348	120,097	121,348	120,097	0	121,348	0
Deposits, Fair Value Disclosure			4,662,794	4,530,411	4,699,282	4,538,137	0	4,669,282	0
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure			106,713	130,791	108,816	133,660	0	108,816	0
Federal Funds Purchased	85,000	0	85,000		85,000		0	85,000	0
Federal Home Loan Bank Borrowings, Fair Value Disclosure			552,946	521,827	577,698	547,584	0	577,698	0
Subordinated Debt Obligations, Fair Value Disclosure			158,647	182,053	131,152	165,242	0	26,454	104,698
Other Liabilities, Fair Value Disclosure			$ 10,746	$ 11,388	$ 10,746	$ 11,388	$ 0	$ 10,746	$ 0

[1] (1)Collateral-dependent impaired loans held at September 30, 2012 that had write-downs in fair value or whose specific reserve changed during the first nine months of 2012.

[2] (1)Collateral-dependent impaired loans held at September 30, 2011 that had write-downs in fair value or whose specific reserve changed during the first nine months of 2011.