Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (loss) - Reclassifications of Accumulated Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Amortization of defined benefit pension and postretirement plan items:
Tax cost	$ (22,085)		$ (19,296)	$ (17,989)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Amortization of defined benefit pension and postretirement plan items:
Prior service cost	60	[1]
Net gain	(523)	[1]
Total before tax	(463)
Tax cost	185
Benefit, net of tax	$ (278)

[1] These amounts are included in the computation of net periodic benefits See Note 16, Employee Benefit Plans, for additional details.