Loans Reconciliation of Carrying Amount of Acquired Impaired Loans (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Reconciliation of Carrying Amount of Acquired Impaired Loans [Abstract]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	$ 1,040,245	$ 1,200,000	$ 1,515,024
Certain Loans Acquired in Transfer, Nonaccretable Difference	(281,445)		(310,213)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, Cash Flows Expected to be Collected at Acquisition	758,800		1,204,811
Certain Loans Acquired in Transfer, Accretable Yield	(102,130)		(161,292)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	$ 656,670	$ 762,386	$ 1,043,519	$ 1,128,978

The investor's estimate, at acquisition, of the amount and timing of undiscounted principal, interest, and other cash flows expected to be collected. This would be the investor's best estimate of cash flows, including the effect of prepayments if considered, that is used in determining the acquisition price, and, in a business combination, the investor's estimate of fair value for purposes of acquisition price allocation. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References+ Details

The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References+ Details

- Definition

The undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loan, owed to the investor at the reporting date, whether or not currently due and whether or not any such amounts have been written or charged off by the investor. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References+ Details