CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 246	$ 236
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	600	600
Common stock, shares, issued	215	215
Treasury stock, shares	71	71