Employee Benefit Plans Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Net (losses) gains	$ (17,630)	$ (75,995)	$ 1,348
Prior service cost	0	0	(1,704)
Amortization of losses	17,578	10,372	6,456
Amortization of prior service cost (benefit)	1,308	1,359	1,657
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Net (losses) gains	(2,021)	(3,934)	(965)
Prior service cost	0	631	0
Amortization of losses	582	570	3,357
Amortization of prior service cost (benefit)	$ 25	$ 69	$ (5,334)