Investments Investments (Investments Held to Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Gain (Loss) on Investments [Line Items]
Amortized Cost	$ 29,288	$ 10,873
Gross Unrealized Gain	3	0
Gross Unrealized (Loss)	(20)	(10)
Fair Value	29,271	10,863
Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost	11,421	2,832
Gross Unrealized Gain	3	0
Gross Unrealized (Loss)	0	(1)
Fair Value	11,424	2,831
Non Current Assets [Member]
Gain (Loss) on Investments [Line Items]
Amortized Cost	17,867	8,041
Gross Unrealized Gain	0	0
Gross Unrealized (Loss)	(20)	(9)
Fair Value	$ 17,847	$ 8,032