Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net income	$ 444	$ 360	$ 85
Adjustments to reconcile net income to net cash from operating activities
Depreciation and amortization	716	658	643
Stock compensation expense	49	79	55
Accretion of debt	15	19	17
Deferred tax expense (benefit)	45	(158)	(21)
Debt extinguishment loss	27	36	70
Unrealized (gain) loss on foreign currency option and forward contracts	(20)	49	(40)
Gain on sale of equity investment	(24)	0	0
Other	0	13	8
Changes in assets and liabilities:
Accounts receivable	(13)	(320)	(154)
Other assets	(49)	(92)	13
Accounts payable	35	140	2
Accrued expenses and other liabilities	(123)	1	(56)
Net cash provided by operating activities	1,102	785	622
Investing activities
Payment for purchases of property and equipment	(551)	(504)	(483)
Proceeds from sale of assets	143	118	69
Proceeds from sale of business, net of $11 cash divested	0	0	548
Other	8	0	8
Net cash (used in) provided by investing activities	(400)	(386)	142
Financing activities
Proceeds from issuance of debt	1,074	819	1,378
Repurchase of debt	(1,225)	(1,387)	(1,889)
Proceeds from borrowings on ABL facility	1,355	995	360
Repayment of borrowings on ABL facility	(1,455)	(925)	(330)
Repayment of long-term debt and capital leases	(119)	(106)	(151)
Payment of debt issuance costs	(10)	(17)	(26)
Proceeds from forward sale settlement	349	0	0
Proceeds from common stock offerings	0	288	0
Repurchase of common stock	(536)	0	0
Change in bank overdrafts	0	(3)	(17)
Payment for tax withholdings for restricted shares	(53)	(17)	(11)
Dividends paid	(8)	(7)	(5)
Other	8	(6)	10
Net cash used in financing activities	(620)	(366)	(681)
Effect of exchange rates on cash, cash equivalents and restricted cash	(17)	16	(4)
Net increase in cash, cash equivalents and restricted cash	65	49	79
Cash, cash equivalents and restricted cash, beginning of year	449	400	321
Cash, cash equivalents and restricted cash, end of year	514	449	400
Supplemental disclosure of cash flow information:
Cash paid for interest	233	274	363
Cash paid for income taxes	$ 70	$ 79	$ 41