Retirement Plans (Net Periodic Benefit Cost) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension settlement costs		$ 40,309		$ 40,309
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	9,170	12,141	29,050	37,809
Interest cost on projected benefit obligation	18,997	18,827	58,645	56,587
Expected return on plan assets	(23,195)	(23,585)	(70,219)	(72,765)
Amortization of prior service cost/(credit)	11	2	33	6
Amortization of unrecognized loss	4,398	10,798	14,036	30,942
Net periodic pension benefit cost	9,381	18,183	31,545	52,579
Pension settlement costs		40,309		40,309
Total periodic benefit cost	9,381	58,492	31,545	92,888
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	2,408	3,088	7,514	9,446
Interest cost on projected benefit obligation	5,470	4,181	15,046	13,061
Expected return on plan assets	(23)	(25)	(37)	(111)
Amortization of prior service cost/(credit)	(890)	(1,526)	(2,670)	(4,576)
Amortization of unrecognized loss	449	1,695	1,893	6,151
Total periodic benefit cost	$ 7,414	$ 7,413	$ 21,746	$ 23,971