Fair Value Measurements Not Measured at Fair Value on a Recurring Basis (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2011 Carrying (Reported) Amount, Fair Value Disclosure [Member]	Jun. 30, 2012 Portion at Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2011 Portion at Fair Value, Fair Value Disclosure [Member]	Jun. 30, 2012 Fair Value, Inputs, Level 1 [Member] Portion at Fair Value, Fair Value Disclosure [Member]	Jun. 30, 2012 Fair Value, Inputs, Level 2 [Member] Portion at Fair Value, Fair Value Disclosure [Member]	Jun. 30, 2012 Fair Value, Inputs, Level 3 [Member] Portion at Fair Value, Fair Value Disclosure [Member]	Jun. 30, 2012 Fair Value, Measurements, Nonrecurring [Member]		Jun. 30, 2011 Fair Value, Measurements, Nonrecurring [Member]		Jun. 30, 2012 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 1 [Member]		Jun. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 1 [Member]		Jun. 30, 2012 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]		Jun. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]		Jun. 30, 2012 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member]		Jun. 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			$ 102,826	$ 203,354		$ 203,354	$ 102,826	$ 0	$ 0
Loans Receivable, Fair Value Disclosure				4,567,183		4,631,890	0	0	5,056,244	8,186	[1]	15,873	[2]	0	[1]	0	[2]	0	[1]	0	[2]	8,186	[1]	15,873	[2]
Other Assets, Fair Value Disclosure				120,097		120,097	0	120,092	0
Deposits, Fair Value Disclosure				4,530,411		4,538,137	0	4,600,469	0
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure			100,842	130,791		133,660	0	103,259	0
Federal Funds Purchased	85,000	0	85,000		85,000		0	85,000	0
Federal Home Loan Bank Borrowings, Fair Value Disclosure			616,749	521,827		547,584	0	642,133	0
Subordinated Debt Obligations, Fair Value Disclosure			174,397	182,053		165,242	0	165,947	0
Other Liabilities, Fair Value Disclosure				$ 11,388		$ 11,388	$ 0	$ 11,136	$ 0

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

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