Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating Activities
Net income	$ 67	$ 24
Adjustments to reconcile net income to net cash:
Depreciation, depletion and amortization	36	36
Loss on extinguishment of debt	2	19
Recovery of receivable	(3)	0
Share-based compensation expense	4	3
Deferred income taxes	29	1
Income from equity method investments	(7)	(8)
Pension settlement	2	0
(Increase) decrease in working capital:
Receivables	(65)	(54)
Income taxes receivable	1	(1)
Inventories	(3)	(2)
Other current assets	5	1
Payables	5	(43)
Accrued expenses	(42)	(23)
Decrease in other assets	1	0
(Decrease) increase in pension and other postretirement benefits	(56)	6
Decrease in other liabilities	(1)	(4)
Other, net	(5)	3
Net cash used for operating activities	(30)	(42)
Investing Activities
Purchases of marketable securities	(79)	(21)
Sales or maturities of marketable securities	84	87
Capital expenditures	(15)	(29)
Net proceeds from asset dispositions	0	1
Return (deposit) of restricted cash	9	(39)
Net cash used for investing activities	(1)	(1)
Financing Activities
Issuance of debt	0	350
Repayment of debt	(64)	(368)
Payment of debt issuance fees	0	(6)
Issuance of common stock	0	3
Repurchases of common stock to satisfy employee tax withholding obligations	(1)	(8)
Net cash used for financing activities	(65)	(29)
Effect of exchange rate changes on cash	1	(3)
Net decrease in cash and cash equivalents	(95)	(75)
Cash and cash equivalents at beginning of period	442	228
Cash and cash equivalents at end of period	347	153
Supplemental Cash Flow Disclosures:
Interest paid, net of capitalized interest	47	50
Income taxes paid, net of refunds received	3	1
Noncash Investing and Financing Activities:
Amount in accounts payable for capital expenditures	$ 3	$ 8