CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Accounts receivable, allowance	$ 106	$ 142
Preferred stock-non-redeemable, par value (in dollars per share)	$ 25.00	$ 25.00
Preferred stock-non-redeemable, authorized shares (shares)	2,000,000	2,000,000
Preferred stock-non-redeemable, issued shares (shares)	7,000	7,000
Preferred stock-non-redeemable, outstanding shares (shares)	7,000	7,000
Common stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common stock, authorized shares (shares)	1,600,000,000	1,600,000,000
Common stock, issued shares (shares)	1,090,058,000	1,080,167,000
Common stock, outstanding shares (shares)	1,090,058,000	1,080,167,000