Goodwill and Identifiable Intangible Assets - Schedule of Reportable Segments by Reporting Units (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Mar. 31, 2015	Sep. 30, 2015
Goodwill [Roll Forward]
Balance at beginning of period	$ 897,933	$ 897,933
Goodwill acquired		64,534
Goodwill adjustment		2,410
Effect of foreign currency translation		(24,696)
Balance at end of period		940,181
Portfolio Purchasing and Recovery [Member]
Goodwill [Roll Forward]
Balance at beginning of period	848,656	848,656
Goodwill acquired		64,534
Goodwill adjustment		2,410
Effect of foreign currency translation		(24,696)
Balance at end of period		890,904
Portfolio Purchasing and Recovery [Member] | Atlantic Credit and Finance, Inc. [Member]
Goodwill [Roll Forward]
Goodwill adjustment	2,400
Goodwill, increase during period	2,400
Tax Lien Transfer [Member]
Goodwill [Roll Forward]
Balance at beginning of period	$ 49,277	49,277
Goodwill acquired		0
Goodwill adjustment		0
Effect of foreign currency translation		0
Balance at end of period		$ 49,277