Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 1,312,000	$ 898,000	$ 915,000
Partners' capital, authorized	250,000,000
Cash and other assets, IP Fund	2,927,000	2,542,000
Patents, net of accumulated amortization, IP Fund	1,373,000	7,144,000
Investments, IP Fund	11,120,000	11,617,000
Total assets, IP Fund	15,420,000	21,303,000
Accrued expenses and contributions, IP Fund	2,437,000	5,016,000
Accrued patent acquisition costs, IP Fund	0	500,000
Total liabilities, IP Fund	2,437,000	5,516,000
Net assets, IP Fund	$ 12,983,000	$ 15,787,000