Receivables - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest-bearing financing fee receivables	$ 86,221,000	$ 69,464,000
Allowance for doubtful accounts receivables	23,540,000	28,777,000	23,017,000	19,450,000
Aggregate carrying amount of non-interest bearing receivables	471,375,000	443,211,000
Financing Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for doubtful accounts receivables	0	0
Trade Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables past due or deemed uncollectible	$ 24,578,000	$ 39,341,000