Investments - Schedule for Cost and Equity Method Investments (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Schedule of Equity Method Investments [Line Items]
Other investments	$ 3,482,000	$ 24,639,000		$ 3,482,000
Equity in loss of unconsolidated affiliate	$ (1,942,000)		$ (410,000)	(3,422,000)	$ (1,569,000)
Impairment on preferred shares				20,696,000
Synthonics
Schedule of Equity Method Investments [Line Items]
Cost method investments	$ 2,170,000	$ 2,170,000		$ 2,170,000
Cost method, ownership percentage	18.30%	19.60%		18.30%
Mindjet
Schedule of Equity Method Investments [Line Items]
Other investments	$ 2,200,000			$ 2,200,000
Voting interest percentage	19.30%			19.30%
Conversion ratio	0.2			0.2
Impairment on preferred shares		$ 1,100,000		$ 20,700,000
Minimum damages	$ 0			0
Maximum damages	1,200,000			1,200,000
Equity Securities | Mindjet
Schedule of Equity Method Investments [Line Items]
Cost method investments	$ 1,312,000	$ 15,858,000		$ 1,312,000
Cost method, ownership percentage	0.00%	13.40%		0.00%
Equity method investments	$ 0	$ 6,611,000		$ 0
Equity method investments, ownership percentage	19.30%	15.00%		19.30%
Other investments	$ 1,312,000	$ 22,469,000		$ 1,312,000
Voting interest percentage	19.30%	28.40%		19.30%
Convertible Debt Securities | Mindjet
Schedule of Equity Method Investments [Line Items]
Cost method investments	$ 851,000			$ 851,000