Investment in Receivable Portfolios, Net - Summary of Accretable Yield and an Estimate of Zero Basis Future Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2017	Sep. 30, 2016
Investment in Receivables Portfolio [Roll Forward]
Balance at beginning of period	$ 3,700,287	$ 3,412,753	$ 3,457,508	$ 3,067,361	$ 3,177,980	$ 3,270,671	$ 3,457,508	$ 3,270,671
Revenue recognized, net	(283,588)	(272,236)	(251,970)	(159,534)	(267,452)	(270,094)	(807,794)	(697,080)
(Reductions) additions on existing portfolios, net	28,701	234,909	(32,692)	322,074	154,594	47,609
Additions for current purchases, net	336,725	258,687	200,728	180,079	183,217	193,654
Effect of foreign currency translation	57,346	66,174	39,179	(75,267)	(180,978)	(63,860)
Balance at end of period	3,839,471	3,700,287	3,412,753	3,334,713	3,067,361	3,177,980	3,839,471	3,334,713
Accretable Yield
Investment in Receivables Portfolio [Roll Forward]
Balance at beginning of period	3,348,792	3,029,588	3,092,004	2,805,694	2,977,955	3,047,640	3,092,004	3,047,640
Revenue recognized, net	(248,220)	(231,431)	(211,718)	(119,543)	(233,714)	(238,547)
(Reductions) additions on existing portfolios, net	27,162	225,021	(90,138)	299,212	59,459	39,538
Additions for current purchases, net	336,725	258,687	200,728	180,079	183,217	193,654
Effect of foreign currency translation	56,971	66,927	38,712	(75,402)	(181,223)	(64,330)
Balance at end of period	3,521,430	3,348,792	3,029,588	3,090,040	2,805,694	2,977,955	3,521,430	3,090,040
Estimate of Zero Basis Cash Flows
Investment in Receivables Portfolio [Roll Forward]
Balance at beginning of period	351,495	383,165	365,504	261,667	200,025	223,031	365,504	223,031
Revenue recognized, net	(35,368)	(40,805)	(40,252)	(39,991)	(33,738)	(31,547)	(116,400)	(105,300)
(Reductions) additions on existing portfolios, net	1,539	9,888	57,446	22,862	95,135	8,071
Additions for current purchases, net	0	0	0	0	0	0
Effect of foreign currency translation	375	(753)	467	135	245	470
Balance at end of period	$ 318,041	$ 351,495	$ 383,165	$ 244,673	$ 261,667	$ 200,025	$ 318,041	$ 244,673