Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Activities
Net income (loss)	$ 38	$ 46	$ (125)
Income (loss) from discontinued operations, net of tax	(1)	(2)	2
Gain on sale of discontinued operations, net of tax	0	0	55
Income (loss) from continuing operations	39	48	(182)
Adjustments to reconcile income (loss) from continuing operations to net cash:
Depreciation, depletion, and amortization	154	155	156
Loss on extinguishment of debt	0	0	41
Litigation settlement charge	48	0	0
Long-lived asset impairment charges	90	0	8
Contract termination charge and loss on receivable	15	0	0
Share-based compensation expense	21	19	17
Deferred income taxes	4	2	4
Provision for bad debt	1	0	7
Gain on asset dispositions	(12)	(1)	(8)
Income from equity method investments	(35)	(1)	0
Pension settlement	13	16	0
Gain on deconsolidation of subsidiaries and consolidated joint ventures	(27)	0	0
(Increase) decrease in working capital:
Receivables	(49)	(44)	6
Income taxes receivable	3	(1)	6
Inventories	(9)	(28)	(12)
Other current assets	2	(4)	5
Payables	10	(4)	27
Accrued expenses	(12)	(23)	14
(Increase) decrease in other assets	3	(6)	1
Decrease in pension and other postretirement benefits	(55)	(63)	(16)
Decrease in other liabilities	(13)	(6)	(5)
Other, net	(18)	21	(1)
Net cash provided by operating activities - continuing operations	173	80	68
Investing Activities
Purchases of marketable securities	(204)	(205)	(137)
Sales or maturities of marketable securities	190	194	291
Capital expenditures	(132)	(124)	(70)
Acquisition of mining rights	0	(17)	(16)
Net proceeds from asset dispositions	16	2	14
Net proceeds from sale of business	0	0	73
Investments in joint ventures, including $23 million of cash of contributed subsidiaries in 2014	(560)	(5)	(14)
Loans to joint ventures	0	0	(4)
Insurance proceeds	3	2	0
Return (deposit) of restricted cash	4	(4)	1
Net cash (used for) provided by investing activities - continuing operations	(683)	(157)	138
Financing Activities
Issuance of debt	3	361	248
Repayment of debt	(63)	(4)	(283)
Payment of debt issuance fees	(3)	(6)	(5)
Loan from venture partner	0	4	4
Issuances of common stock	4	4	4
Repurchases of common stock to satisfy employee tax withholding obligations	(7)	(9)	(6)
Net cash (used for) provided by financing activities - continuing operations	(66)	350	(38)
Net cash (used for) provided by operating activities - discontinued operations	(1)	(2)	10
Net cash used for investing activities - discontinued operations	0	0	(1)
Effect of exchange rate changes on cash	(5)	(7)	4
Net increase (decrease) in cash and cash equivalents	(582)	264	181
Cash and cash equivalents at beginning of period	810	546	365
Cash and cash equivalents at end of period	228	810	546
Supplemental Cash Flow Disclosures:
Interest paid, net of interest capitalized	172	192	200
Income taxes paid, net of refunds received	7	10	1
Noncash Investing and Financing Activities:
Amount in accounts payable for capital expenditures	15	13	10
Contribution of wholly-owned subsidiaries and joint venture investments as consideration for investments in USG Boral Building Products	121	0	0
Conversion of $75 million and $325 million, respectively, of 10% convertible senior notes due 2018, net of discount	(73)	(314)	0
Issuance of common stock upon conversion of debt	75	313	0
Acceleration of deferred financing fee amortization to additional paid-in capital	0	1	0
Accrued interest on debt conversion	$ (2)	$ 0	$ 0