Investment in Receivable Portfolios, Net - Summary of Changes in Balance of Investment in Receivable Portfolios (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period	$ 1,590,249		$ 873,119
Purchases of receivable portfolios	467,565	58,771
Gross collections	(396,674)	(270,170)
Put-backs and recalls	(3,384)	(878)
Foreign currency adjustments	8,706
Revenue recognized	234,338	139,677
Portfolio allowance reversals, net	3,230	1,006
Balance, end of period	1,904,030	801,525	873,119
Revenue as a percentage of collections	59.10%	51.70%
Accrual Basis Portfolios [Member]
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period	1,585,587		873,119
Purchases of receivable portfolios	467,565	58,771
Gross collections	(389,503)	(264,559)
Put-backs and recalls	(3,235)	(878)
Foreign currency adjustments	8,706
Revenue recognized	230,747	135,015
Portfolio allowance reversals, net	310	57
Balance, end of period	1,900,177	801,525	873,119
Revenue as a percentage of collections	59.20%	51.00%
Cost Recovery Portfolios [Member]
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period	4,662
Purchases of receivable portfolios	0
Gross collections	(660)
Put-backs and recalls	(149)
Balance, end of period	3,853
Revenue as a percentage of collections	0.00%	0.00%
Zero Basis Portfolios [Member]
Investment in Receivables Portfolio [Roll Forward]
Gross collections	(6,511)	(5,611)
Put-backs and recalls	0
Revenue recognized	3,591	4,662
Portfolio allowance reversals, net	2,920	949
Revenue as a percentage of collections	55.20%	83.10%
Marlin [Member]
Investment in Receivables Portfolio [Roll Forward]
Purchases of receivable portfolios	$ 208,500