Investments (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax	$ (13,900,000)
Investment in Marketable Securities (Textual) [Abstract]
Unrealized gain (loss) on available for sale securities	(8,489,000)	(3,351,000)	(4,975,000)
Impairment loss	18,308,000	605,000	0
Short term investments	0	999,000	20,254,000
Marketable securities [Member]
Available-for-sale Securities
Cost	17,649,000	34,786,000
Gross Unrealized Losses	(3,300,000)	(10,443,000)
Gross Unrealized Gains	172,000	2,722,000
Available-for-sale Securities, Estimated Fair Value	14,521,000	27,065,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Unrealized Losses, Less than twelve months	(3,300,000)
Unrealized Losses, Twelve months or more	0
Unrealized Losses Total	(3,300,000)	(10,443,000)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value, Less than twelve months	4,146,000
Fair Value, Twelve months or more	0
Fair Value, Total	$ 4,146,000