Additional Shareholders' Equity Information (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Common stock shares issued [Rollforward]
Shares, beginning of period (in shares)	396,697,484	393,313,692
Exercise of common stock options (in shares)	1,892,962	2,530,462
Restricted stock awards, net of forfeitures (in shares)	1,251,271	853,330
Shares, end of period (in shares)	399,841,717	396,697,484	393,313,692
Treasury stock [Rollforward]
Shares, beginning of period (in shares)	37,550,752	37,473,040
Shares received from employees in payment of withholding taxes due on vesting of shares of restricted stock (in shares)	250,307	282,248
Rabbi Trust Shares Distributed and/or Sold (in shares)	(201,008)	(204,536)
Shares, end of period (in shares)	37,600,051	37,550,752	37,473,040
Components And Changes In Accumulated Other Comprehensive Income [Line Items]
Beginning Balance	$ (113)	$ (100)	$ (104)
Realized Amounts Reclassified Into Earnings	13	7	5
Unrealized Change in Fair Value	(17)	(20)	(1)
End Balance	(117)	(113)	(100)
Effective income tax rate applied to AOCI (in hundredths)	35.00%	35.00%	35.00%
Interest rate cash flow hedges [Member]
Components And Changes In Accumulated Other Comprehensive Income [Line Items]
Beginning Balance	(25)	(26)	(42)
Realized Amounts Reclassified Into Earnings	1	1	1
Unrealized Change in Fair Value	0	0	15
End Balance	(24)	(25)	(26)
Pension-related and other [Member]
Components And Changes In Accumulated Other Comprehensive Income [Line Items]
Beginning Balance	(88)	(74)	(62)
Realized Amounts Reclassified Into Earnings	12	6	4
Unrealized Change in Fair Value	(17)	(20)	(16)
End Balance	$ (93)	$ (88)	$ (74)