Investments (Narrative) (Details) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010	Jan. 26, 2010 Sapphire Industrials Corp. [Member]	Jan. 24, 2008 Sapphire Industrials Corp. [Member]	Jun. 30, 2011 LAM Alternative Asset Management Funds [Member]	Dec. 31, 2010 LAM Alternative Asset Management Funds [Member]	Jun. 30, 2011 Edgewater [Member]	Dec. 31, 2010 Edgewater [Member]
Equity method investments - purchase of warrants					$ 12,500
Equity method investments - purchase of common stock	11,281		11,291		50,000
Equity method investments -distribution from company dissolution				50,319
Pre-tax unrealized available-for-sale investment gains	0	5,456
Pre-tax unrealized available-for-sale investment losses	0	6,013
GP interests consolidated, but owned by noncontrolling interests						5,735	8,219
Private equity investments consolidated, but owned by noncontrolling interests								$ 74,505	$ 67,206