Consolidated Statement of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred	$ (79,899)	$ (189,259)	$ (95,007)
Net Income (Loss)	659,056	388,073	632,497
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Treasury Rate Lock, Net of Tax	0	0	(96)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	456,493	129,231	(32,813)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	45,631	114,240	200,700
Net Income (Loss)	659,056	388,073	632,497
Other Comprehensive Income (Loss), Net of Tax	422,225	54,212	72,784
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	1,081,281	442,285	705,281
Less: Comprehensive Loss (Income), Net of Tax, Attributable to Noncontrolling Interest	1,386	397	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 1,082,667	$ 442,682	$ 705,281