Retirement Plans (Net Periodic Benefit Cost) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 9,940	$ 12,834	$ 19,880	$ 25,668
Interest cost on projected benefit obligation	19,824	18,880	39,648	37,760
Expected return on plan assets	(23,512)	(24,590)	(47,024)	(49,180)
Amortization of prior service cost/(credit)	11	2	22	4
Amortization of unrecognized loss	4,819	10,072	9,638	20,144
Net periodic benefit cost	11,082	17,198	22,164	34,396
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	2,553	3,179	5,106	6,358
Interest cost on projected benefit obligation	4,788	4,440	9,576	8,880
Expected return on plan assets	(7)	(43)	(14)	(86)
Amortization of prior service cost/(credit)	(890)	(1,525)	(1,780)	(3,050)
Amortization of unrecognized loss	722	2,228	1,444	4,456
Net periodic benefit cost	$ 7,166	$ 8,279	$ 14,332	$ 16,558