CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Property and equipment, accumulated depreciation and amortization	$ 5,960	$ 6,043
Other intangible assets, accumulated amortization	$ 1,374	$ 1,284
Common stock, par value (in dollars per share)	$ 0.05	$ 0.05
Common stock, number of shares authorized (in shares)	262,500,000	262,500,000
Common stock, number of shares issued (in shares)	155,520,691	154,407,524
Common stock, number of shares held in treasury (in shares)	48,331,649	48,337,947