Fair Value Measurements (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Changes in assets
Balance at the beginning of the period	$ 3,876,259	$ 3,624,986
Total gains (losses) included in earnings / losses	165,714	289,922
Total gains (losses) included in other comprehensive gain	404	154
Purchases	92,397	95,911
Premiums paid		233
Interest accreted	42,452	36,103
Payments received	(111,239)	(100,256)
Asset distribution		(11,507)
Balance at the end of the period	4,065,987	3,935,546
Amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the end of the period	165,714	289,975
VIE and other finance receivables, at fair market value
Changes in assets
Balance at the beginning of the period	3,870,649	3,615,188
Total gains (losses) included in earnings / losses	165,714	289,987
Purchases	92,397	95,911
Interest accreted	42,452	36,103
Payments received	(111,080)	(99,034)
Asset distribution		(9,615)
Balance at the end of the period	4,060,132	3,928,540
Amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the end of the period	165,714	289,987
Life settlement contracts, at fair market value
Changes in assets
Balance at the beginning of the period		1,724
Total gains (losses) included in earnings / losses		(65)
Premiums paid		233
Asset distribution		(1,892)
Amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the end of the period		(12)
Notes receivable, at fair market value
Changes in assets
Balance at the beginning of the period	5,610	8,074
Total gains (losses) included in other comprehensive gain	404	154
Payments received	(159)	(1,222)
Balance at the end of the period	$ 5,855	$ 7,006