Employee Benefit Plans (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Noncurrent Liability	$ 54,768	$ 51,006
Pension Benefit Plan
Current Liability	(345)	(303)
Noncurrent Liability	(24,568)	(23,702)
Net Liability Recognized	(24,913)	(24,005)
Other Benefits Plan
Current Liability
Noncurrent Liability	(30,200)	(27,304)
Net Liability Recognized	$ (30,200)	$ (27,304)