Retirement Plans (Amounts Recognized as a Component of AOCI) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2013 Pension Benefits [Member]	Dec. 31, 2012 Pension Benefits [Member]	Dec. 31, 2013 Postretirement Benefits Other Than Pensions (OPEB) [Member]	Dec. 31, 2012 Postretirement Benefits Other Than Pensions (OPEB) [Member]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Accumulated other comprehensive income at beginning of year				$ 697,874	$ 575,163	$ 74,264	$ 41,811
Net actuarial gain (loss) recognized during year				(36,930)	(29,890)	(7,846)	(7,537)
Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), before Tax				(8)	199	6,101	10,068
Net actuarial loss (gain) occurring during year				(205,341)	152,402	(67,289)	30,665
Prior service cost (credit) occurring during year							(743)
Settlement costs recognized during year	(3,900)	(40,300)	(44,163)	(44,163)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax				(286,442)	122,711	(69,034)	32,453
Accumulated other comprehensive income at end of year				$ 411,432	$ 697,874	$ 5,230	$ 74,264