Investment in Receivable Portfolios, Net - Change in the Balance of the Investment in Receivable Portfolios (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period	$ 3,211,587	$ 3,137,893	$ 3,024,141	$ 2,890,613	$ 3,137,893	$ 2,890,613
Purchases of receivable portfolios	242,697		359,580		505,032	636,342
Transfer of portfolios	0				0
Transfers to assets held for sale	(2,327)		(2,295)		(5,916)	(5,367)
Collections on receivable portfolios	(514,881)		(496,093)		(1,028,734)	(985,195)
Put-Backs and Recalls	(1,395)		(8,508)		(5,095)	(12,328)
Foreign currency adjustments	(25,671)		(102,498)		(5,695)	(40,558)
Revenue recognized	312,495	311,158	292,662	281,009	623,653	573,671
Portfolio (allowance) reversals, net	2,063	1,367	17,632	9,811	3,430	27,443
Reclassification adjustment			0			0
Balance, end of period	$ 3,224,568	3,211,587	$ 3,084,621	3,024,141	$ 3,224,568	$ 3,084,621
Revenue as a percentage of collections	60.70%		59.00%		60.60%	58.20%
Accrual Basis Portfolios
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period	$ 3,203,892	3,129,502	$ 3,013,519	2,879,170	$ 3,129,502	$ 2,879,170
Purchases of receivable portfolios	242,697		359,580		505,032	636,342
Transfer of portfolios	(78,980)				(78,980)
Transfers to assets held for sale	(813)		(2,033)		(3,958)	(5,105)
Collections on receivable portfolios	(484,018)		(460,478)		(969,616)	(915,621)
Put-Backs and Recalls	(1,392)		(8,484)		(5,086)	(12,175)
Foreign currency adjustments	(26,756)		(101,921)		(6,619)	(40,331)
Revenue recognized	285,562		258,698		570,817	508,519
Portfolio (allowance) reversals, net	(255)		15,411		(1,155)	23,493
Reclassification adjustment			0			0
Balance, end of period	$ 3,139,937	3,203,892	$ 3,074,292	3,013,519	$ 3,139,937	$ 3,074,292
Revenue as a percentage of collections	59.00%		56.20%		58.90%	55.50%
Cost Recovery Portfolios
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period	$ 7,695	8,391	$ 10,622	11,443	$ 8,391	$ 11,443
Purchases of receivable portfolios	0		0		0	0
Transfer of portfolios	78,980				78,980
Transfers to assets held for sale	(1,514)		(262)		(1,958)	(262)
Collections on receivable portfolios	(1,615)		(252)		(1,706)	(1,423)
Put-Backs and Recalls	0		0		0	0
Foreign currency adjustments	1,085		(577)		924	(227)
Revenue recognized	0		0		0	0
Portfolio (allowance) reversals, net	0		0		0	0
Reclassification adjustment			798			798
Balance, end of period	$ 84,631	7,695	$ 10,329	10,622	$ 84,631	$ 10,329
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	$ 0	$ 0
Purchases of receivable portfolios	0		0		0	0
Transfer of portfolios	0				0
Transfers to assets held for sale	0		0		0	0
Collections on receivable portfolios	(29,248)		(35,363)		(57,412)	(68,151)
Put-Backs and Recalls	(3)		(24)		(9)	(153)
Foreign currency adjustments	0		0		0	0
Revenue recognized	26,933		33,964
Portfolio (allowance) reversals, net	2,318		2,221		4,585	3,950
Reclassification adjustment			(798)			(798)
Balance, end of period	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Revenue as a percentage of collections	92.10%		96.00%		92.00%	95.60%