Ownership, Description of Business, and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended												1 Months Ended	12 Months Ended	1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Cabot Acquisition [Member]	Dec. 31, 2013 AACC Merger [Member]	Dec. 31, 2013 Propel Acquisition [Member]	Dec. 31, 2013 2017 Convertible Senior Notes [Member]	Dec. 31, 2012 2017 Convertible Senior Notes [Member]	Nov. 27, 2012 2017 Convertible Senior Notes [Member]	Feb. 06, 2014 2017 Convertible Senior Notes [Member] Subsequent Event [Member]	Dec. 31, 2012 2017 Convertible Senior Notes [Member] Before Amendment [Member]	Dec. 16, 2013 2017 Convertible Senior Notes [Member] After Amendment [Member]	Jan. 31, 2013 Maximum [Member]	Dec. 31, 2013 Maximum [Member]	Jan. 31, 2013 Minimum [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Percentage of payment made for portfolios purchase	50.00%
Foreclosure rate														0.50%
Business acquisition, date of acquisition				Jul. 01, 2013	Jun. 13, 2013	May 08, 2012
Deferred Court Costs not recovered, years	3 years
Increase in deferral period													5 years		3 years
Typical lien to value ratio, percentage														15.00%
Rare lien to value ratio, percentage														25.00%
Allowance for financial receivables	$ 0
Employee stock options to purchase common shares, excluded from computation of diluted earnings per share	0	352,000	167,000
Initial conversion price per share							$ 31.56		$ 31.56
Common shares issuable upon conversion of convertible senior notes							115,000,000
Warrants sold to purchase common stock							358,000	3,600,000		3,200,000
Warrants exercise price											44.19	60
Convertible senior notes issuance	$ 287,500,000	$ 115,000,000						$ 115,000,000	$ 115,000,000