Parent Company Financial Statements (Parent Company Statement of Comprehensive Income) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net income	$ 1,729	$ 2,028	$ 1,332
OCI, Net of Tax
Change in unrecognized pension and postretirement amounts	(411)	111	235
Change in unrecognized gains (losses) on cash flow hedges	175	(14)	(112)
Other, net	(1)	13	(37)
Total OCI	(34)	154	34
Total comprehensive income	1,695	2,182	1,366
Income Tax Effect Of Items Included In OCI
Change in unrecognized pension and postretirement amounts	(252)	70	143
Change in unrecognized gains (losses) on cash flow hedges	106	(9)	(67)
Other, net	2	6	(21)
Parent Company [Member]
Net income	1,729	2,028	1,332
OCI, Net of Tax
Change in unrecognized pension and postretirement amounts	(4)
Change in unrecognized gains (losses) on cash flow hedges	0	(2)	(1)
Other, net	1	1	(8)
Total OCI	(3)	(1)	(9)
Total comprehensive income	1,726	2,027	1,323
Income Tax Effect Of Items Included In OCI
Change in unrecognized pension and postretirement amounts	(1)
Change in unrecognized gains (losses) on cash flow hedges	0	(1)	0
Other, net	$ 0	$ 0	$ (4)