Accounting Policies and Basis of Presentation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended	3 Months Ended			0 Months Ended
	Sep. 30, 2012	Sep. 30, 2012	Jun. 30, 2012 Noncovered Loans	Sep. 30, 2012 Noncovered Loans	Mar. 31, 2012 Noncovered Loans	Jul. 31, 2012 Debenture Of 1998 Subordinated Debt	Jul. 31, 2012 Debenture Of 1998 Secured Debt	Jul. 31, 2012 Preferred Securities of 1998 Securities Sold under Agreements to Repurchase	Jul. 15, 2012 Securitization and Sale of Revolving Mortgage Loans in 2005 Secured Debt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maximum period of fair value refinement after transaction closing date		1 year
Adjustments to acquisition gains	$ 0
Threshold amount for individual impairment analysis				500	1,000
Impact of change in estimation method on allowance			2,615
Stated interest rate for debt (percent)						8.05%
Face value of debt instrument						154,640		150,000
Amount of debt redeemed						163,569		158,661
Redeemed debt face amount (percent)						102.42%
Reductions in long-term borrowings from repayments of debt							154,640		21,565
Prepayment penalty interest rate (percent)							2.42%
Prepayment penalty expense							$ 3,630