Business Combinations - Components of Purchase Price Allocation (Detail) £ in Millions	Jun. 01, 2015 USD ($)	Jun. 01, 2015 GBP (£)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Allocation of purchase price:
Goodwill			$ 890,504,000	$ 924,847,000
dlc [Member]
Business Acquisition [Line Items]
Cash paid at acquisition	$ 268,391,000
Deferred consideration	6,306,000
Total purchase price	274,697,000	£ 180.6
Allocation of purchase price:
Cash	30,518,000
Investment in receivable portfolios	215,988,000
Deferred court costs	760,000
Property and equipment	1,327,000
Other assets	2,384,000
Liabilities assumed	(46,435,000)
Identifiable intangible assets	3,669,000
Goodwill	66,486,000
Total net assets acquired	274,697,000
Amount of goodwill deductible for income tax purposes	$ 0