CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Ownership interest in and advances, to partner companies and funds, fair value	$ 14,560	$ 20,972
Preferred stock, par value	$ 0.10	$ 0.10
Preferred stock, shares authorized	1,000	1,000
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	83,333	83,333
Common stock, shares issued	21,519	20,968
Common stock, shares outstanding	21,519	20,968