Other Comprehensive Income (Loss) (Schedule of Components of Accumulated Other Comprehensive Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	$ (2,607)	$ (3,435)	$ (2,621)	$ (3,307)
Other comprehensive income (loss) before reclassifications	(325)	171	(378)	(49)
Amounts reclassified from accumulated other comprehensive income	37	51	104	143
Other comprehensive income (loss), net of tax	(288)	222	(274)	94
Balance, end of period	(2,895)	(3,213)	(2,895)	(3,213)
Unrealized Investment Gains [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	5	3	5	4
Other comprehensive income (loss) before reclassifications	0	0	0	(1)
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Other comprehensive income (loss), net of tax	0	0	0	(1)
Balance, end of period	5	3	5	3
Pension/Postretirement Plans Gains (Losses) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	(2,883)	(3,238)	(2,682)	(3,451)
Other comprehensive income (loss) before reclassifications	94	(85)	(174)	36
Amounts reclassified from accumulated other comprehensive income	37	51	104	143
Other comprehensive income (loss), net of tax	131	(34)	(70)	179
Balance, end of period	(2,752)	(3,272)	(2,752)	(3,272)
Foreign Currency Translation Adjustments [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	271	(200)	56	140
Other comprehensive income (loss) before reclassifications	(419)	256	(204)	(84)
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Other comprehensive income (loss), net of tax	(419)	256	(204)	(84)
Balance, end of period	$ (148)	$ 56	$ (148)	$ 56