Investment in Receivable Portfolios, Net - Summary of Accretable Yield and an Estimate of Zero Basis Future Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield and Estimate of Zero Basis Future Cash Flows Movement Schedule [Roll Forward]
Beginning balance	$ 4,064,701	$ 3,457,508
Revenue from receivable portfolios	(1,167,132)	(1,053,373)	$ (1,030,792)
(Reversal of) provision for allowances on receivable portfolios, net	(41,473)	(41,236)	84,177
Net additions on existing portfolios	162,840	520,517
Additions for current purchases, net	1,155,451	1,019,856
Effect of foreign currency translation	(148,181)	161,429
Ending balance	4,026,206	4,064,701	3,457,508
Accretable Yield
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield and Estimate of Zero Basis Future Cash Flows Movement Schedule [Roll Forward]
Beginning balance	3,695,069	3,092,004
Revenue from receivable portfolios	(1,041,947)	(909,239)
(Reversal of) provision for allowances on receivable portfolios, net	(32,429)	(34,294)
Net additions on existing portfolios	144,726	365,357
Additions for current purchases, net	1,155,451	1,019,856
Effect of foreign currency translation	(147,699)	161,385
Ending balance	3,773,171	3,695,069	3,092,004
Estimate of Zero Basis Cash Flows
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield and Estimate of Zero Basis Future Cash Flows Movement Schedule [Roll Forward]
Beginning balance	369,632	365,504
Revenue from receivable portfolios	(125,185)	(144,134)
(Reversal of) provision for allowances on receivable portfolios, net	(9,044)	(6,942)
Net additions on existing portfolios	18,114	155,160
Additions for current purchases, net	0	0
Effect of foreign currency translation	(482)	44
Ending balance	$ 253,035	$ 369,632	$ 365,504