Fair Value Measurements - Additional Information (Detail) (USD $)						12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013 Cabot Acquisition [Member]	Dec. 31, 2013 Cost to collect [Member]	Dec. 31, 2013 Discount rate [Member]	Dec. 31, 2013 United States [Member]	Dec. 31, 2012 United Kingdom [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Increase or decrease of the fair value						$ 19,500,000	$ 18,100,000
Fluctuation in discount rate	1.00%
Estimated market participant cost to collect								50.30%	29.70%
Discount rate								12.00%	18.20%
Carrying value of investment in receivable portfolios	1,590,249,000	873,119,000	716,454,000	644,753,000
Convertible senior notes, carrying value	287,500,000	115,000,000
Convertible senior notes, debt discount	42,240,000	14,442,000
Fair value estimate of convertible senior notes incorporates quoted market prices	412,400,000	128,300,000			680,700,000
Senior secured notes, carrying value	58,750,000	72,500,000			646,900,000
Senior secured notes, debt premium	$ 43,583,000				$ 43,600,000