Stockholders' Equity (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Stockholders' Equity (Textuals) [Abstract]
Stock Issued During Period, Shares, New Issues	61
Equity Issuance, Per Share Amount	$ 57.00
Common Units Sold In Offering	8
Proceeds from issuance of common stock	$ 3,378			$ 3,408	$ 9
Statement [Line Items]
Total, Beginning Balance				(164)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				(20)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				10
Other comprehensive income (loss)		42	(20)	3	(32)
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net				47
Total, Ending Balance	(194)	(194)		(194)
Reclassifications Out Of Accumulated Other Comprehensive Income [Abstract]
Product sales		853	1,046	1,783	2,150
Reclassifications before income tax		(207)	(302)	(454)	(629)
Provision (benefit) for income taxes		(84)	(102)	(135)	(198)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassifications Out Of Accumulated Other Comprehensive Income [Abstract]
Provision (benefit) for income taxes				(5)
Reclassifications during the period				10
Cash flow hedging activities [Member]
Statement [Line Items]
Total, Beginning Balance				(1)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				0
Other comprehensive income (loss)				0
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net				0
Total, Ending Balance	(1)	(1)		(1)
Foreign currency translation [Member]
Statement [Line Items]
Total, Beginning Balance				128
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				(20)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				0
Other comprehensive income (loss)				(20)
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net				(20)
Total, Ending Balance	88	88		88
Accumulated Other Comprehensive Income (Loss) [Member]
Statement [Line Items]
Other comprehensive income (loss)				(10)
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net				(20)
Pension and other postretirement benefits [Member]
Statement [Line Items]
Total, Beginning Balance				(291)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				10
Other comprehensive income (loss)				10
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net				0
Total, Ending Balance	(281)	(281)		(281)
Pension and other postretirement benefits [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassifications Out Of Accumulated Other Comprehensive Income [Abstract]
Amortization of prior service cost (credit) included in net periodic benefit cost				(4)
Amortization of actuarial (gain) loss included in net periodic benefit cost				19
Reclassifications before income tax				15
Parent [Member]
Statement [Line Items]
Other comprehensive income (loss)				(10)
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net				$ (99)