Loan Loss Allowance and Credit Quality - Summary of Activity in Loan Loss Allowance Related to Purchased Receivables Portfolios (Details) (Purchased Receivables Portfolios, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Purchased Receivables Portfolios
Accounts Notes And Loans Receivable [Line Items]
Balance — beginning of period	$ 226,356	$ 218,640
Incremental provisions for purchased receivable portfolios	1,325	21,662
Incremental reversal of provisions for purchased receivable portfolios	(21,511)	(56,110)
Balance — end of period	$ 206,170	$ 184,192