Segment Information - Reconciliation of Revenue and Operating Income from Segments to Consolidated (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	$ 237,099	$ 235,558	$ 156,121	$ 144,586	$ 143,903	$ 145,218	$ 141,246	$ 126,410	$ 773,364	$ 556,777	$ 448,746
Depreciation and amortization									(13,547)	(5,840)	(4,081)
Other expense									(77,491)	(24,756)	(21,511)
Income from continuing operations before income taxes									120,868	130,325	98,669
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues									773,364	556,777	448,746
Operating income loss before depreciation and amortization									224,555	169,715	131,970
Operating Segments [Member] | Portfolio Purchasing and Recovery [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues									756,277	545,419	448,746
Operating income loss before depreciation and amortization									219,510	164,038	131,970
Operating Segments [Member] | Tax Lien Transfer [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues									17,087	11,358
Operating income loss before depreciation and amortization									5,045	5,677
Segment Reconciling Items [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization									(13,547)	(5,840)	(4,081)
Stock-based compensation									(12,649)	(8,794)	(7,709)
Other expense									$ (77,491)	$ (24,756)	$ (21,511)