Significant Accounting Policy Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (325,117)	$ (747,342)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax	(367,610)	(824,103)
Other Comprehensive Income (Loss), Net of Tax	422,225	54,212	72,784
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	42,493	76,761
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	185,881
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	236,344
Postretirement Benefit Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Net of Tax	456,493
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	140,250
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	316,243
Cash Flow Hedging [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Net of Tax	(34,268)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	45,631
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ (79,899)