Investment in Receivable Portfolios, Net - Summary of Changes in Balance of Investment in Receivable Portfolios (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period	$ 2,436,018	$ 2,486,978	$ 2,382,809	$ 2,440,669
Purchases of receivable portfolios	246,415	233,116	465,142	489,869
Transfer of portfolios		0
Disposals or transfers to held for sale	(2,697)	0	(7,468)
Gross collections	(446,182)	(434,100)	(887,045)	(881,905)
Put-backs and Recalls	(3,237)	(3,557)	(5,027)	(16,550)
Foreign currency adjustments	53,372	(80,296)	83,308	(100,036)
Revenue recognized	263,407	264,973	513,245	532,876
Portfolio allowance reversals, net	8,829	2,479	10,961	4,670
Balance, end of period	$ 2,555,925	$ 2,469,593	$ 2,555,925	$ 2,469,593
Revenue as a percentage of collections	59.00%	61.00%	57.90%	60.40%
Accrual Basis Portfolios
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period	$ 2,422,299	$ 2,482,855	$ 2,368,366	$ 2,436,054
Purchases of receivable portfolios	245,246	233,116	463,973	489,869
Transfer of portfolios		96
Disposals or transfers to held for sale	(2,697)	0	(7,468)
Gross collections	(404,918)	(399,498)	(804,922)	(815,225)
Put-backs and Recalls	(3,237)	(3,692)	(4,994)	(16,577)
Foreign currency adjustments	53,466	(80,432)	83,486	(100,319)
Revenue recognized	224,310	233,010	435,415	471,088
Portfolio allowance reversals, net	7,121	704	7,734	1,173
Balance, end of period	$ 2,541,590	$ 2,465,967	$ 2,541,590	$ 2,465,967
Revenue as a percentage of collections	55.40%	58.30%	54.10%	57.80%
Cost Recovery Portfolios
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period	$ 13,719	$ 4,123	$ 14,443	$ 4,615
Purchases of receivable portfolios	1,169	0	1,169	0
Transfer of portfolios		(96)
Disposals or transfers to held for sale	0	0	0
Gross collections	(459)	(724)	(1,099)	(1,357)
Put-backs and Recalls	0	(5)	0	(11)
Foreign currency adjustments	(94)	136	(178)	283
Revenue recognized	0	0	0	0
Portfolio allowance reversals, net	0	0	0	0
Balance, end of period	$ 14,335	$ 3,626	$ 14,335	$ 3,626
Revenue as a percentage of collections	0.00%	0.00%	0.00%	0.00%
Zero Basis Portfolios
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period	$ 0	$ 0	$ 0	$ 0
Purchases of receivable portfolios	0	0	0	0
Transfer of portfolios		0
Disposals or transfers to held for sale	0	0	0
Gross collections	(40,805)	(33,878)	(81,024)	(65,323)
Put-backs and Recalls	0	140	(33)	38
Foreign currency adjustments	0	0	0	0
Revenue recognized	39,097	31,963	77,830	61,788
Portfolio allowance reversals, net	1,708	1,775	3,227	3,497
Balance, end of period	$ 0	$ 0	$ 0	$ 0
Revenue as a percentage of collections	95.80%	94.30%	96.10%	94.60%