Derivatives (Schedule of Derivative Assets/Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Derivative Liabilities Noncurrent	$ 12	$ 0
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets, Current	888	151
Derivative Assets, Noncurrent	54	0
Derivative Liabilities, Current	(29)	(702)
Derivative Liabilities Noncurrent	(11)	0
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets, Current	3,448	2,716
Derivative Assets, Noncurrent	696	0
Derivative Liabilities, Current	(831)	(4,885)
Derivative Liabilities Noncurrent	(1)	0
Total [Member]
Derivatives, Fair Value [Line Items]
Net Fair value of derivatives	$ 4,214	$ (2,720)