Investments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Investment in Marketable Securities (Textual) [Abstract]
Unrealized gain (loss) on available for sale securities	$ (1,312)	$ (773)	$ (2,813)	$ (401)
Impairment of equity securities	(31)	$ (934)	(1,545)	$ (3,522)
Marketable securities [Member]
Available-for-sale Securities
Cost	4,285		4,285		$ 5,687
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	939		939		8
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax	870		870		303
Available-for-sale Securities, Estimated Fair Value					$ 5,982
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than twelve Months, Fair Value	932		932
Twelve months or more, Fair Value	0		0
Fair Value	932		932
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 939		$ 939