CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowance (in dollars)	$ 146	$ 158
Customer relationships, accumulated amortization	2,811	2,524
Other intangible assets, accumulated amortization	$ 1,022	$ 956
Preferred stock-non-redeemable, par value (in dollars per share)	$ 25.00	$ 25.00
Preferred stock-non-redeemable, authorized shares	2,000	2,000
Preferred stock-non-redeemable, issued shares	7	7
Preferred stock-non-redeemable, outstanding shares	7	7
Common stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common stock, authorized shares	1,600,000	1,600,000
Common stock, issued shares	615,564	625,658
Common stock, outstanding shares	615,564	625,658