Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating activities
Net income (loss)	$ 276	$ (109)
Adjustments to reconcile net income (loss) to net cash from operating activities
Depreciation, amortization and net lease activity	397	379
Stock compensation expense	25	39
Accretion of debt	10	8
Deferred tax (benefit) expense	(1)	3
Debt extinguishment loss	8	0
Unrealized (gain) loss on foreign currency option and forward contracts	1	(1)
Gains on sales of property and equipment	(31)	(39)
Other	5	42
Changes in assets and liabilities
Accounts receivable	(240)	186
Other assets	(77)	(84)
Accounts payable	(21)	(277)
Accrued expenses and other liabilities	187	247
Net cash provided by operating activities	539	394
Investing activities
Payment for purchases of property and equipment	(250)	(255)
Proceeds from sale of property and equipment	62	77
Other	34	6
Net cash used in investing activities	(154)	(172)
Financing activities
Proceeds from issuance of debt	0	1,161
Proceeds from (repayment of) borrowings related to securitization program	(49)	109
Repurchase of debt	(1,200)	0
Proceeds from borrowings on ABL facility	0	620
Repayment of borrowings on ABL facility	(200)	(20)
Repayment of debt and finance leases	(53)	(40)
Payment for debt issuance costs	(5)	(21)
Purchase of noncontrolling interests	(128)	0
Repurchase of common stock	0	(114)
Change in bank overdrafts	14	23
Payment for tax withholdings for restricted shares	(22)	(18)
Other	4	1
Net cash provided by (used in) financing activities	(1,639)	1,701
Effect of exchange rates on cash, cash equivalents and restricted cash	1	(15)
Net increase (decrease) in cash, cash equivalents and restricted cash	(1,253)	1,908
Cash, cash equivalents and restricted cash, beginning of period	2,065	387
Cash, cash equivalents and restricted cash, end of period	812	2,295
Supplemental disclosure of cash flow information
Leased assets obtained in exchange for new operating lease liabilities, including $281 related to an acquisition in 2021	711	371
Leased assets obtained in exchange for new finance lease liabilities	41	17
Cash paid for interest	136	149
Cash paid for income taxes	$ 65	$ 10