Investments (Investments Held to Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Gain (Loss) on Investments [Line Items]
Amortized Cost	$ 19,338	$ 15,987
Gross Unrealized Gain	7	0
Gross Unrealized (Loss)	(5)	(23)
Fair Value	19,340	15,964
Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost	8,266	11,972
Gross Unrealized Gain	7	0
Gross Unrealized (Loss)	0	(7)
Fair Value	8,273	11,965
Non Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost	11,072	4,015
Gross Unrealized Gain	0	0
Gross Unrealized (Loss)	(5)	(16)
Fair Value	$ 11,067	$ 3,999