Retirement Plans (Net Periodic Benefit Cost) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension settlement costs	$ 4,000	$ 40,000	$ 44,163
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost			47,651	41,649	43,688
Interest cost on projected benefit obligation			75,812	80,476	78,027
Expected return on plan assets			(94,695)	(99,273)	(95,777)
Amortization of prior service cost/(credit)			8	45	(199)
Amortization of unrecognized loss			36,930	19,951	29,890
Net periodic pension benefit cost			65,706	42,848	55,629
Pension settlement costs			44,163
Total periodic benefit cost			109,869	42,848	55,629
Amortization of prior service cost/(credit) expected in 2015				45
Amortization of unrecognized loss expected in 2015				27,773
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost			12,533	10,799	10,812
Interest cost on projected benefit obligation			17,241	21,739	17,842
Expected return on plan assets			(136)	(50)	(172)
Amortization of prior service cost/(credit)			(6,101)	(3,911)	(10,068)
Amortization of unrecognized loss			7,846	2,916	7,537
Total periodic benefit cost			31,383	31,493	25,951
Amortization of prior service cost/(credit) expected in 2015				(4,205)
Amortization of unrecognized loss expected in 2015				$ 10,819