Employee Benefit Plans Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Deferred income tax benefit	$ (40,525)	$ (36,889)
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service cost	(5,707)	(7,062)
Net losses	(110,728)	(191,813)
Negative plan amendment	0	0
Deferred income tax benefit	36,685	61,968
AOCI	(79,750)	(136,907)
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service cost	(49)	(328)
Net losses	(8,057)	(11,939)
Negative plan amendment	3,574	521
Deferred income tax benefit	1,571	4,073
AOCI	$ (2,961)	$ (7,673)