Finance Receivables - Summary of Finance Receivables Held for Investment (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	$ 21,444,601	[1]	$ 20,219,609
Receivables from dealers held for investment	85,194	[2]	94,745
Unsecured consumer loans	1,233,637	[3]	954,189
Loans Acquired Individually
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	20,383,317		18,566,121
Purchased Receivables Portfolios
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	1,061,284		1,653,488
Receivables from Dealers Held for Investments
Accounts Notes And Loans Receivable [Line Items]
Receivables from dealers held for investment	85,194		94,745
Unsecured Consumer Loans
Accounts Notes And Loans Receivable [Line Items]
Unsecured consumer loans	1,233,637		954,189
Unpaid Principal Balance
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	24,948,696		23,199,341
Unpaid Principal Balance | Loans Acquired Individually
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	23,675,889		21,238,281
Unpaid Principal Balance | Purchased Receivables Portfolios
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	1,272,807		1,961,060
Unpaid Principal Balance | Receivables from Dealers Held for Investments
Accounts Notes And Loans Receivable [Line Items]
Receivables from dealers held for investment	85,885		95,835
Unpaid Principal Balance | Unsecured Consumer Loans
Accounts Notes And Loans Receivable [Line Items]
Unsecured consumer loans	1,448,709		1,165,778
Loan Loss Allowance
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	(2,866,431)		(2,358,990)
Loan Loss Allowance | Loans Acquired Individually
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	(2,668,587)		(2,132,634)
Loan Loss Allowance | Purchased Receivables Portfolios
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	(197,844)		(226,356)
Loan Loss Allowance | Receivables from Dealers Held for Investments
Accounts Notes And Loans Receivable [Line Items]
Receivables from dealers held for investment	(923)		(1,090)
Loan Loss Allowance | Unsecured Consumer Loans
Accounts Notes And Loans Receivable [Line Items]
Unsecured consumer loans	(212,954)		(179,350)
Discount
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	(672,833)		(654,678)
Discount | Loans Acquired Individually
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	(659,154)		(573,462)
Discount | Purchased Receivables Portfolios
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	(13,679)		(81,216)
Discount | Receivables from Dealers Held for Investments
Accounts Notes And Loans Receivable [Line Items]
Receivables from dealers held for investment	0		0
Discount | Unsecured Consumer Loans
Accounts Notes And Loans Receivable [Line Items]
Unsecured consumer loans	(3,067)		(32,831)
Capitalized Origination Costs and Fees
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	35,169		33,936
Capitalized Origination Costs and Fees | Loans Acquired Individually
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	35,169		33,936
Capitalized Origination Costs and Fees | Purchased Receivables Portfolios
Accounts Notes And Loans Receivable [Line Items]
Retail installment contracts held for investment, net	0		0
Capitalized Origination Costs and Fees | Receivables from Dealers Held for Investments
Accounts Notes And Loans Receivable [Line Items]
Receivables from dealers held for investment	232		0
Capitalized Origination Costs and Fees | Unsecured Consumer Loans
Accounts Notes And Loans Receivable [Line Items]
Unsecured consumer loans	$ 949		$ 592

[1] Retail installment contracts held for investment — Retail installment contracts held for investment are carried at amortized cost, net of loan loss allowance. The estimated fair value is calculated based on estimated market rates for similar contracts with similar credit risks and is considered a Level 3 measurement.

[2] Receivables from dealers, held for investment, net — Receivables from dealers held for investment are carried at amortized cost, net of loan loss allowance. The estimated fair value is calculated based on estimated market rates for similar receivables with similar credit risks and is considered a Level 3 measurement.

[3] Unsecured consumer loans, net — Unsecured consumer loans are carried at amortized cost, net of loan loss allowance. Carrying value approximates fair value for unsecured revolving loans because the loans are short term in duration, do not have a defined maturity date and/or are at a market-based interest rate. For unsecured amortizing loans, the estimated fair value is calculated based on estimated market rates for similar loans with similar credit risks and is considered a level 3 measurement.