Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Transfer of Liabilities, amount	$ 0		$ 0
Transfer of assets, amount	0		0
Assets fair value non-recurring	0	$ 0	0
Liabilities fair value non-recurring	0	0	0
Accrual for losses on consumer loan guaranty obligations	$ 1,200,000	$ 1,700,000	$ 900,000
Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalent maturity period	90 days
Maximum | Short-term Loans
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Term of loan	12 months
Maximum | Line of Credit Accounts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Term of loan	12 months
Maximum | Installment Loans and RPAs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Term of loan	60 months
Maximum | RPAs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Estimated delivery term	36 months
Minimum | Installment Loans and RPAs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Term of loan	2 months
Minimum | RPAs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Estimated delivery term	6 months