Investment in Receivable Portfolios, Net - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended					6 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Initial collection forecast			120 months
Extended collection forecast			180 months
Allowance charges	$ (682)			$ 0		$ (682)	$ 0
Reduction in allowance charges	9,511			2,479		11,643	4,670
Face value of receivable portfolios	2,400,000			2,800,000		4,100,000	6,400,000
Purchase price of receivable portfolios	$ 246,415			$ 233,116		$ 465,142	$ 489,869
Purchase cost as a percentage of face value	10.10%			8.20%		11.30%	7.70%
Estimated future collections at acquisition for receivable portfolios	$ 505,000			$ 416,900		$ 924,400	$ 875,500
Revenue recognized, net	272,236	$ 251,970		267,452	$ 270,094	524,206	537,546
Estimate of Zero Basis Cash Flows
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Revenue recognized, net	40,805	$ 40,252		$ 33,738	$ 31,547	$ 81,100	$ 65,300
Investment in Receivable Portfolios
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Increase in total estimated remaining collections for receivable portfolios			$ 296,500
Europe | Investment in Receivable Portfolios
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Allowance charges			$ 94,000
Reduction in allowance charges	$ 7,800