Investments (Investments Held to Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Gain (Loss) on Investments [Line Items]
Amortized Cost	$ 6,977	$ 15,987
Gross Unrealized Gain	9	0
Gross Unrealized (Loss)	(10)	(23)
Fair Value	6,976	15,964
Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost	4,984	11,972
Gross Unrealized Gain	9	0
Gross Unrealized (Loss)	0	(7)
Fair Value	4,993	11,965
Non Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost	1,993	4,015
Gross Unrealized Gain	0	0
Gross Unrealized (Loss)	(10)	(16)
Fair Value	$ 1,983	$ 3,999