Investments (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Proceeds from Sale of Short-term Investments	$ 49,100,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Marketable Securities	5,200,000
Realized Gain (Loss) on Marketable Securities, Cost Method Investments, and Other Investments	600,000
Investment in Marketable Securities (Textual) [Abstract]
Unrealized gain (loss) on equity securities	(2,290,000)	(8,489,000)	(3,351,000)
Impairment of equity securities	(6,593,000)	(18,308,000)	(605,000)
Equity securities [Member]
Available-for-sale Securities
Cost	5,687,000	17,649,000
Gross Unrealized Losses	(8,000)	(3,300,000)
Gross Unrealized Gains	303,000	172,000
Available-for-sale Securities, Estimated Fair Value	5,982,000	14,521,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Unrealized Losses Total	(8,000)	(3,300,000)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than twelve Months, Unrealized Losses	(8,000)
Less than twelve Months, Fair Value	38,000
Twelve months or more, Unrealized Losses	0
Twelve months or more, Fair Value	0
Unrealized Losses	(8,000)
Fair Value	$ 38,000