Investment in Receivable Portfolios, Net - Summary of Changes in Balance of Investment in Receivable Portfolios (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period				$ 2,440,669				$ 2,143,560	$ 2,440,669	$ 2,143,560	$ 1,590,249
Purchases of receivable portfolios									906,719	1,023,722	1,251,360
Transfer of portfolios									0		0
Gross collections	$ (396,738)	$ (406,961)	$ (434,100)	(447,805)	$ (416,577)	$ (421,753)	$ (437,324)	(425,071)	(1,685,604)	(1,700,725)	(1,607,497)
Put-backs and Recalls									(28,613)	(13,297)	(15,709)
Foreign currency adjustments									(196,977)	(85,027)	(67,675)
Revenue recognized									1,030,792	1,065,673	975,425
Portfolio (allowance) reversals, net									(84,177)	6,763	17,407
Balance, end of period	2,382,809				2,440,669				$ 2,382,809	$ 2,440,669	$ 2,143,560
Revenue as a percentage of collections									61.20%	62.70%	60.70%
Accrual Basis Portfolios [Member]
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period				2,436,054				2,131,084	$ 2,436,054	$ 2,131,084	$ 1,585,587
Purchases of receivable portfolios									906,719	1,023,722	1,249,651
Transfer of portfolios									(13,076)		(18,682)
Gross collections									(1,538,663)	(1,587,525)	(1,563,996)
Put-backs and Recalls									(27,561)	(13,009)	(15,164)
Foreign currency adjustments									(196,842)	(82,443)	(64,644)
Revenue recognized									892,732	969,227	953,154
Portfolio (allowance) reversals, net									(90,997)	(5,002)	5,178
Balance, end of period	2,368,366				2,436,054				$ 2,368,366	$ 2,436,054	$ 2,131,084
Revenue as a percentage of collections									58.00%	61.10%	60.90%
Cost Recovery Portfolios [Member]
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period				4,615				12,476	$ 4,615	$ 12,476	$ 4,662
Purchases of receivable portfolios									0	0	1,709
Transfer of portfolios									13,076		18,682
Gross collections									(2,102)	(5,237)	(9,010)
Put-backs and Recalls									(1,019)	(20)	(536)
Foreign currency adjustments									(127)	(2,604)	(3,031)
Revenue recognized									0	0	0
Portfolio (allowance) reversals, net									0	0	0
Balance, end of period	14,443				4,615				$ 14,443	$ 4,615	$ 12,476
Revenue as a percentage of collections									0.00%	0.00%	0.00%
Zero Basis Portfolios [Member]
Investment in Receivables Portfolio [Roll Forward]
Balance, beginning of period				$ 0				$ 0	$ 0	$ 0	$ 0
Purchases of receivable portfolios									0	0	0
Transfer of portfolios									0		0
Gross collections									(144,839)	(107,963)	(34,491)
Put-backs and Recalls									(33)	(268)	(9)
Foreign currency adjustments									(8)	20	0
Revenue recognized									138,060	96,446	22,271
Portfolio (allowance) reversals, net									6,820	11,765	12,229
Balance, end of period	$ 0				$ 0				$ 0	$ 0	$ 0
Revenue as a percentage of collections									95.30%	89.30%	64.60%