Investments (Investments Held to Maturity) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Gain (Loss) on Investments [Line Items]
Amortized Cost	$ 7,139	$ 14,083
Gross Unrealized Gain	0	0
Gross Unrealized (Loss)	(3)	(12)
Fair Value	7,136	14,071
Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost	7,139	14,083
Gross Unrealized Gain	0	0
Gross Unrealized (Loss)	(3)	(12)
Fair Value	7,136	14,071
Non Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost	0	0
Gross Unrealized Gain	0	0
Gross Unrealized (Loss)	0	0
Fair Value	$ 0	$ 0