CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
OPERATING ACTIVITIES:
Net income (loss)	$ 201	$ (52)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization expense	54	52
Amortization of deferred debt financing costs	2	2
Gain (loss) on sale of assets	210	(4)
Stock-based compensation expense	9	5
Deferred income taxes	(3)	(14)
Other, net	(12)	2
Change in working capital, net of effects of acquisitions and dispositions	(44)	5
Changes in noncurrent assets and liabilities, net	6	5
Net cash provided by operating activities	3	9
INVESTING ACTIVITIES:
Purchase of property, plant and equipment	(81)	(62)
Acquisition of businesses, net of cash acquired	(4)	(16)
Proceeds from the sale of assets, net	111	0
Property insurance proceeds	7	2
Payment of indemnification claim from sale of asset	(7)	0
Other, net	0	(1)
Net cash provided by (used in) investing activities	26	(77)
FINANCING ACTIVITIES:
Proceeds from borrowings on long-term debt	0	400
Proceeds from borrowings on revolving credit facility	170	331
Proceeds from borrowings on project debt	0	33
Payments on long-term debt	(1)	(1)
Payment on revolving credit facility	(228)	(288)
Payments on equipment financing capital leases	(1)	(1)
Payments on project debt	(10)	(9)
Payment of deferred financing costs	0	(8)
Cash dividends paid to stockholders	(33)	(33)
Financing of insurance premiums, net	(7)	0
Other, net	0	(3)
Net cash (used in) provided by financing activities	(110)	421
Effect of exchange rate changes on cash and cash equivalents	3	1
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	(78)	354
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	116	548
Cash, cash equivalents and restricted cash at end of period	51	444
Restricted funds held in trust	42	52
Restricted funds held in trust	$ 23	$ 52