Investments (Investments Held to Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Gain (Loss) on Investments [Line Items]
Amortized Cost	$ 23,835	$ 27,021
Gross Unrealized Gain	32	18
Gross Unrealized (Loss)	0	0
Fair Value	23,867	27,039
Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost	22,808	16,040
Gross Unrealized Gain	31	11
Gross Unrealized (Loss)	0	0
Fair Value	22,839	16,051
Non Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost	1,027	10,981
Gross Unrealized Gain	1	7
Gross Unrealized (Loss)	0	0
Fair Value	$ 1,028	$ 10,988