Investments (Investments Held to Maturity) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Gain (Loss) on Investments [Line Items]
Amortized Cost	$ 15,195	$ 17,483
Gross Unrealized Gain	5	0
Gross Unrealized (Loss)	0	(33)
Fair Value	15,200	17,450
Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost	15,195	12,444
Gross Unrealized Gain	5	0
Gross Unrealized (Loss)	0	(16)
Fair Value	15,200	12,428
Non Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost	0	5,039
Gross Unrealized Gain	0	0
Gross Unrealized (Loss)	0	(17)
Fair Value	$ 0	$ 5,022