Segment Information - Reconciliation of Revenue and Operating Income from Segments to Consolidated (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	$ 156,121	$ 141,246	$ 300,707	$ 267,656
Depreciation and amortization	(2,158)	(1,420)	(4,004)	(2,660)
Stock-based compensation	(2,179)	(2,539)	(5,180)	(4,805)
Other expense	(11,604)	(6,603)	(18,299)	(11,851)
Income from continuing operations before income taxes	18,279	31,834	50,298	61,602
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	156,121	141,246	300,707	267,656
Operating income loss before depreciation and amortization	34,220	42,396	77,781	80,918
Operating Segments [Member] | Portfolio purchasing and recovery [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	152,091	138,733	292,774	265,143
Operating income loss before depreciation and amortization	33,478	41,396	76,158	79,918
Operating Segments [Member] | Tax lien business [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	4,030	2,513	7,933	2,513
Operating income loss before depreciation and amortization	$ 742	$ 1,000	$ 1,623	$ 1,000