Pension and Postretirement Plans (Consolidated Balance Sheet) (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Noncurrent asset	$ 1,152,488	$ 1,245,505
Current liability	0	0
Noncurrent liability	0	0
Recognized asset (liability)	1,152,488	1,245,505
Supplemental Executive Retirement Plan (SERP) [Member]
Defined Benefit Plan Disclosure [Line Items]
Noncurrent asset	0	0
Current liability	(6,275)	(4,251)
Noncurrent liability	(109,808)	(86,918)
Recognized asset (liability)	(116,083)	(91,169)
Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liability	(3,995)	(3,795)
Noncurrent liability	(37,962)	(36,219)
Recognized asset (liability)	$ (41,957)	$ (40,014)