Investments (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Investments
Fair value of investments	$ 18,889,000	$ 20,478,000
Total investment gains, net	1,267,000	1,233,000	2,996,000
Unrecognized carried interest	2,900,000	1,600,000
Investment in FATV
Investments
Fair value of investments	17,624,000	17,110,000
Total investment gains, net	3,800,000	1,261,000	2,188,000
Employee Investment Funds net of Company's ownership interest
Investments
Fair value of investments	1,265,000	1,218,000
Total investment gains, net	(36,000)	(28,000)	(39,000)
Other investments
Investments
Fair value of investments		2,150,000	1,200,000
Total investment gains, net	$ (2,497,000)		$ 847,000