Investments (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended					12 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Trilantic [Member]	Dec. 31, 2010 Trilantic [Member]	Dec. 31, 2011 Pan [Member]	Dec. 31, 2010 Pan [Member]	Dec. 31, 2009 Pan [Member]	Dec. 31, 2011 G5 [Member]	Dec. 31, 2010 G5 [Member]	Oct. 31, 2010 G5 [Member]	Dec. 31, 2009 CSIP [Member]	Dec. 31, 2010 CSI Capital [Member]	Dec. 31, 2011 Minimum [Member] ECP II [Member]	Dec. 31, 2011 Maximum [Member] ECP II [Member]	Dec. 31, 2011 Other Expenses [Member]
Schedule of Equity Method Investments [Line Items]
Carried interest earned by the general partner, percent																						8.00%	9.00%
Existing commitment to CSI Capital, percent					58.00%					58.00%
Net realized and unrealized gains (losses) on private equity fund investments, including performance fees									$ 6,200	$ 2,148	$ (5,179)
Previously received carried interest subject to repayment	2,701								2,701
Notes due date														2016
Number of seats holds in board														3
Total number of board seats														6
Equity method investment												15,549	15,840	4,158							3,164
Equity method investment in Pan and maintains, percent														50.00%
Carrying value of notes receivable	667								667
Income (Loss) from Equity Method Investments	255	195	69	400	(116)	(131)	(130)	(180)	919	(557)	(1,406)			(420)	(621)	(1,406)	1,340	64
Cost basis investment																				$ 1,250				$ 1,250
Cost basis investments exchange noncontrolling interest, percent											5.00%								50.00%