Investments (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Equity method investment
Amount of equity method investment	$ 18,889,000	$ 20,478,000
Assets:
Cash and cash equivalents	51,353,000	44,868,000	36,672,000	40,009,000
Total Assets	95,964,000	1,229,306,000
Partners' Capital:
Total Liabilities and Stockholders' Equity	95,964,000	1,229,306,000
Expenses:
Professional fees	11,184,000	9,643,000	4,503,000
Other	3,584,000	2,880,000	3,262,000
Total expenses	29,542,000	29,088,000	23,233,000
Net gains on investments	1,267,000	1,233,000	2,996,000
Investment in FATV
Equity method investment
Amount of equity method investment	17,600,000	17,100,000
Open commitments to fund portfolio	0
Total partnership capital	77,269,000	70,949,000
Share in management fee income	500,000	600,000	600,000
Assets:
Investments at fair value	75,188,000	69,736,000
Cash and cash equivalents	786,000	1,220,000
Escrow receivable and other	1,352,000	46,000
Total Assets	77,326,000	71,002,000
Liabilities:
Accrued expenses and other liabilities	57,000	53,000
Partners' Capital:
Partner's capital	77,269,000	70,949,000
Total Liabilities and Stockholders' Equity	77,326,000	71,002,000
Revenue:
Interest income	1,000	428,000	37,000
Expenses:
Management fees	532,000	576,000	582,000
Professional fees	61,000	57,000	74,000
Other	3,000	6,000	49,000
Total expenses	596,000	639,000	705,000
Net investment loss	(595,000)	(211,000)	(668,000)
Net gains on investments	19,417,000	7,454,000	11,507,000
Net increase in partners' capital from operations	$ 18,822,000	$ 7,243,000	$ 10,839,000