Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating activities
Net income (loss)	$ (11)	$ 333
Adjustments to reconcile net income (loss) to net cash from operating activities
Depreciation, amortization and net lease activity	572	546
Stock compensation expense	50	48
Accretion of debt	14	16
Deferred tax expense	4	26
Debt extinguishment loss	0	5
Unrealized (gain) loss on foreign currency option and forward contracts	(1)	5
Gains on sales of property and equipment	(68)	(73)
Other	46	17
Changes in assets and liabilities
Accounts receivable	(152)	(190)
Other assets	(52)	(12)
Accounts payable	(105)	(153)
Accrued expenses and other liabilities	395	(126)
Net cash provided by operating activities	692	442
Investing activities
Payment for purchases of property and equipment	(377)	(413)
Proceeds from sale of property and equipment	148	192
Cash collected on deferred purchase price receivable	0	186
Other	5	0
Net cash used in investing activities	(224)	(35)
Financing activities
Proceeds from issuance of debt	1,155	1,751
Proceeds from borrowings related to securitization program	48	0
Proceeds from borrowings on ABL facility	820	1,690
Repayment of borrowings on ABL facility	(620)	(1,690)
Repayment of debt and finance leases	(65)	(850)
Payment for debt issuance costs	(21)	(28)
Purchase of noncontrolling interests	(21)	0
Repurchase of common stock	(114)	(1,347)
Change in bank overdrafts	20	2
Payment for tax withholdings for restricted shares	(21)	(11)
Other	1	4
Net cash provided by (used in) financing activities	1,182	(479)
Effect of exchange rates on cash, cash equivalents and restricted cash	(2)	(7)
Net increase (decrease) in cash, cash equivalents and restricted cash	1,648	(79)
Cash, cash equivalents and restricted cash, beginning of period	387	514
Cash, cash equivalents and restricted cash, end of period	2,035	435
Supplemental disclosure of cash flow information
Leased assets obtained in exchange for new operating lease liabilities	481	559
Leased assets obtained in exchange for new finance lease liabilities	32	35
Cash paid for interest	215	202
Cash paid for income taxes	$ 20	$ 89