CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE OPERATIONS (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current Fiscal Year End Date	--12-31
Net Income	$ 508	$ 316	$ 245
Related to marketable securities:
Unrealized holding gains and losses arising during the period	(9)	9	(1)
Reclassification adjustment for gains and losses included in net income	(2)	(7)	(3)
Income tax benefit (expense)	4	(1)	1
Marketable securities, net of tax	(7)	1	(3)
Related to employee benefit plans:
Actuarial gains and losses related to pension and other postretirement benefit plans	358	(107)	(199)
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax	42	39	24
Income tax benefit	(150)	25	65
Employee benefit plans, net of tax	250	(43)	(110)
Related to interest rate derivative instruments:
Unrealized holding gains and losses arising during the period	10	(10)	(26)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	6	6	6
Income tax benefit	(6)	0	10
Interest rate derivative instruments, net of tax	10	(4)	(10)
Other comprehensive loss	253	(46)	(123)
Comprehensive income	$ 761	$ 270	$ 122