Usg (USG) 10-Q 23 Oct 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014
Document and Entity Information [Abstract]	'
Entity Registrant Name	'USG CORP
Entity Central Index Key	'0000757011
Document Type	'10-Q
Document Period End Date	30-Sep-14
Amendment Flag	'false
Document Fiscal Year Focus	'2014
Document Fiscal Period Focus	'Q3
Current Fiscal Year End Date	'--12-31
Entity Filer Category	'Large Accelerated Filer
Entity Common Stock, Shares Outstanding	144,731,928

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended				9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Income Statement [Abstract]	'		'		'		'
Net sales	$972	[1]	$925	[2]	$2,770	[1],[2]	$2,655	[2]
Cost of products sold	796		770		2,276		2,225
Gross profit	176		155		494		430
Selling and administrative expenses	76		80		230		229
Litigation settlement charge	48		0		48		0
Long-lived asset impairment charges	30		0		30		0
Restructuring charges	0		0		0		3
Operating profit	22	[1]	75	[2]	186	[1],[2]	198	[2]
Income from equity method investments	-12		-1		-20		-2
Interest expense	43		51		135		151
Interest income	0		-1		-1		-3
Gain on deconsolidation of subsidiaries and consolidated joint ventures	0		0		-27		0
Income (loss) from continuing operations before income taxes	-9		26		99		52
Income tax expense	2		2		7		1
Income (loss) from continuing operations	-11		24		92		51
Loss from discontinued operations, net of tax	0		-1		-1		-1
Net income (loss)	-11		23		91		50
Less: Net income attributable to noncontrolling interest	1		0		1		0
Net income (loss) attributable to USG	($12)		$23		$90		$50
Earnings (loss) per common share - basic:	'		'		'		'
Income (loss) from continuing operations	($0.09)		$0.23		$0.65		$0.48
Loss from discontinued operations	$0		($0.01)		($0.01)		($0.01)
Earnings per average common share	($0.09)		$0.22		$0.64		$0.47
Earnings (loss) per common share - diluted:	'		'		'		'
Income (loss) from continuing operations	($0.09)		$0.22		$0.63		$0.47
Loss from discontinued operations	$0		($0.01)		($0.01)		($0.01)
Earnings per average diluted common share	($0.09)		$0.21		$0.62		$0.46
Average common shares	144,646,284		108,608,086		140,944,207		108,486,583
Average diluted common shares	144,646,284		111,008,421		147,087,399		111,052,333
[1]	Gypsum's operating profit for both the three and nine months ended September 30, 2014 included a litigation settlement charge of $48 million and long-lived asset impairment charges of $30 million
[2]	Net sales and operating profit (loss) have been recast for periods prior to April 1, 2014 to conform with the new presentation of reportable segments.

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net income	($11)	$23	$91	$50
Derivatives qualifying as cash flow hedges:	'	'	'	'
Gain/(loss) on derivatives qualifying as cash flow hedges, net of tax of $1, $0, $1, and $1, respectively	-1	-2	1	0
Less: Reclassification adjustment for gain on derivatives included in net income, net of tax of $0, $1, $0 and $1, respectively	1	0	4	0
Net derivatives qualifying as cash flow hedges	-2	-2	-3	0
Pension and postretirement benefits:	'	'	'	'
Changes in pension and postretirement benefits, net of tax of $1, $0, $2 and $2, respectively	3	-3	-6	-15
Less: Amortization of prior service credit (cost) included in net periodic pension cost, net of tax benefit of $0, $0, ($1) and ($1), respectively	3	-3	9	-8
Net pension and postretirement benefits	0	0	-15	-7
Foreign currency translation:	'	'	'	'
Changes in foreign currency translation, net of tax of $0 in all periods	-39	5	-28	-12
Less: Translation gains realized upon the deconsolidation of foreign subsidiaries, net of tax of $0	0	0	5	0
Net foreign currency translation	-39	5	-33	-12
Other comprehensive income (loss), net of tax	-41	3	-51	-19
Comprehensive income (loss)	($52)	$26	$40	$31

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (Parentheticals) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivatives Qualifying as Hedges, Tax:	'	'	'	'
Loss on derivatives qualifying as cash flow hedges, tax expense (benefit)	$1	$0	$1	$1
Less: Reclassification adjustment for loss on derivatives included in net income, tax expense (benefit)	0	1	0	1
Pension and Other Postretirement Benefit Plans, Tax:	'	'	'	'
Changes in pension and postretirement benefits, tax expense (benefit)	1	0	2	2
Less: Amortization of prior service benefit (cost) included in net periodic pension cost, tax expense (benefit)	0	0	-1	-1
Foreign Currency Translation Adjustment, Tax:	'	'	'	'
Changes in foreign currency translation, tax expense (benefit)	0	0	0	0
Less: Translation gains realized upon sale of foreign entities, tax expense (benefit)	$0	$0	$0	$0

Consolidated_Balance_Sheets_Un

Consolidated Balance Sheets (Unaudited) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets	'	'
Cash and cash equivalents	$240	$810
Short-term marketable securities	64	82
Restricted cash	1	5
Receivables (net of reserves - $11 and $12)	434	369
Inventories	326	332
Income taxes receivable	7	3
Deferred income taxes	51	52
Other current assets	53	47
Total current assets	1,176	1,700
Long-term marketable securities	36	60
Property, plant and equipment (net of accumulated depreciation and depletion - $1,909 and $1,840)	1,953	2,103
Deferred income taxes	12	17
Equity method investments	739	73
Other assets	148	168
Total assets	4,064	4,121
Liabilities and Stockholders’ Equity	'	'
Accounts payable	257	284
Accrued expenses	206	216
Current portion of long-term debt	4	63
Income taxes payable	0	5
Litigation settlement accrual	48	0
Total current liabilities	515	568
Long-term debt	2,206	2,238
Long-term debt - related party	0	54
Deferred income taxes	70	66
Pension and other postretirement benefits	246	277
Other liabilities	261	256
Total liabilities	3,298	3,459
Preferred stock	0	0
Common stock	14	14
Additional paid-in capital	3,007	2,920
Accumulated other comprehensive income (loss)	-27	24
Retained earnings (accumulated deficit)	-2,230	-2,320
Stockholders’ equity of parent	764	638
Noncontrolling interest	2	24
Total stockholders’ equity including noncontrolling interest	766	662
Total liabilities and stockholders’ equity	$4,064	$4,121

Consolidated_Balance_Sheets_Un1

Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Reserves on receivables	$11	$12
Accumulated depreciation	$1,909	$1,840

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Operating Activities	'	'
Net income	$91	$50
Loss from discontinued operations, net of tax	-1	-1
Income from continuing operations	92	51
Adjustments to reconcile income from continuing operations to net cash:	'	'
Depreciation, depletion and amortization	115	115
Litigation settlement charge	48	0
Long-lived asset impairment charges	30	0
Share-based compensation expense	16	14
Deferred income taxes	4	-1
Gain on asset dispositions	-12	-1
Income from equity method investments	-20	-2
Gain on deconsolidation of subsidiaries and consolidated joint ventures	-27	0
(Increase) decrease in working capital, net of deconsolidation of subsidiaries and consolidated joint ventures:	'	'
Receivables	-70	-57
Income taxes receivable	-1	0
Inventories	-6	-24
Other current assets	-1	-14
Payables	-16	-14
Accrued expenses	-6	-4
Decrease in other assets	0	0
Decrease in pension and other postretirement benefits	-48	-59
Decrease in other liabilities	-12	-4
Other, net	-6	12
Net cash provided by operating activities	80	12
Investing Activities	'	'
Purchases of marketable securities	-126	-152
Sales or maturities of marketable securities	166	144
Capital expenditures	-88	-72
Acquisition of mining rights	0	-17
Net proceeds from asset dispositions	14	1
Investment in joint venture, including $23 million of cash of contributed subsidiaries in 2014	-558	-5
Insurance proceeds	3	0
Return (deposit) of restricted cash	4	-1
Net cash used for investing activities	-585	-102
Financing Activities	'	'
Issuance of debt	3	7
Repayment of debt	-62	-3
Loans from joint venture partner	0	3
Issuance of common stock	4	3
Repurchases of common stock to satisfy employee tax withholding obligations	-7	-9
Net cash (used for) provided by financing activities	-62	1
Effect of exchange rate changes on cash	-2	-4
Net cash used for operating activities - discontinued operations	-1	-1
Net decrease in cash and cash equivalents	-570	-94
Cash and cash equivalents at beginning of period	810	546
Cash and cash equivalents at end of period	240	452
Supplemental Cash Flow Disclosures:	'	'
Interest paid, net of capitalized interest	127	137
Income taxes paid, net	9	4
Noncash Investing and Financing Activities:	'	'
Amount in accounts payable for capital expenditures	7	8
Contribution of wholly-owned subsidiaries and joint venture investments as consideration for investment in USG Boral Building Products	121	0
Conversion of $75 million of 10% convertible senior notes due 2018, net of discount	-73	0
Issuance of common stock upon conversion of debt	75	0
Accrued interest on debt conversion	($2)	$0

Consolidated_Statements_of_Cas1

Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Statement of Cash Flows [Abstract]	'
Cash on hand at the subsidiaries contributed to UBBP	$23
Debt converted	$75

Organization_Consolidation_and

Organization, Consolidation and Presentation of Financial Statements	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Organization, Consolidation and Presentation of Financial Statements	'
	Organization, Consolidation and Presentation of Financial Statements
	PREPARATION OF FINANCIAL STATEMENTS
	We prepared the accompanying unaudited consolidated financial statements of USG Corporation in accordance with applicable United States Securities and Exchange Commission, or SEC, guidelines pertaining to interim financial information. The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America, or U.S. GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses. Actual results could differ materially from those estimates. In the opinion of our management, the financial statements reflect all adjustments, which are of a normal recurring nature, necessary for a fair presentation of our financial results for the interim periods. The results of operations for the three and nine months ended September 30, 2014 are not necessarily indicative of the results of operations to be expected for the entire year.
	On our consolidated statements of operations for the three months and nine months ended September 30, 2013, income from equity method investments, which was previously included in "Other income, net," is reflected as "Income from equity method investments" to conform to the current year presentation. On our consolidated statement of cash flow for the nine months ended September 30, 2013, income from equity method investments previously included in "Other, net" has been reclassified to "Income from equity method investments."
	Our investment with Boral Limited in a 50/50 joint venture, USG Boral Building Products or UBBP, was consummated on February 27, 2014 (February 28, 2014 Eastern Standard Time (Australia)), and as a result, seven months of results of UBBP were recorded in our accompanying consolidated statement of operations for the nine months ended September 30, 2014. See Note 2 for further description of our investment in UBBP.
	Effective April 1, 2014, we changed the composition of our reportable segments to reflect the change in management over our businesses in Mexico and Latin America and the contribution of our businesses in Asia-Pacific, India and Oman into UBBP. Accordingly, our segments are now structured around our key products and business units: (1) Gypsum, (2) Ceilings, (3) Distribution and (4) UBBP. As a result of these changes, our Mexico and Latin America businesses have been combined, with their Gypsum results included within our Gypsum segment, previously referred to as North American Gypsum, and their Ceiling results included within our Ceilings segment, previously referred to as Worldwide Ceilings. Our prior period results have been recast to reflect these changes and present comparative year over year results. See Notes 2 and 4.
	These financial statements and notes are to be read in conjunction with the financial statements and notes included in USG’s Annual Report on Form 10-K for the fiscal year ended December 31, 2013, which we filed with the SEC on March 3, 2014.
	RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS
	In April 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2014-08, "Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity," which includes amendments that change the requirements for reporting discontinued operations and require additional disclosures about discontinued operations. Under the new guidance, only disposals representing a strategic shift in operations - that is, a major effect on the organization's operations and financial results - should be presented as discontinued operations. Examples include a disposal of a major geographic area, a major line of business, or a major equity method investment. Additionally, ASU 2014-08 requires expanded disclosures about discontinued operations that will provide financial statement users with more information about the assets, liabilities, income, and expenses of discontinued operations. This update is effective for us in the first quarter of 2015. We do not expect that the adoption of ASU 2014-08 will have a significant impact to our consolidated financial statements or disclosures.
	In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers.” ASU 2014-09 supersedes the revenue recognition requirements in “Revenue Recognition (Topic 605),” and requires entities to recognize revenue in a way that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. The standard will be effective for us in the first quarter of 2017, with early adoption not permitted. There are two transition methods available under the new standard, either cumulative effect or retrospective. We are currently evaluating the impact of this ASU and have not yet selected a transition method.
	In August 2014, the FASB issued ASU 2014-15, "Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern," which requires management to assess, at each annual and interim reporting period, the entity's ability to continue as a going concern within one year of date of the financial statements are issued and provide related disclosures. The new standard will be effective for us for the year ended December 31, 2016, with early adoption permitted. We do not expect that the adoption of ASU 2014-15 will have a significant impact to our consolidated financial statements or disclosures.

Equity_Method_Investments

Equity Method Investments	9 Months Ended
	Sep. 30, 2014
Equity Method Investments and Joint Ventures [Abstract]	'
Equity Method Investments	'
	Equity Method Investments
	Equity method investments as of September 30, 2014 and December 31, 2013, were as follows:
			30-Sep-14				31-Dec-13
	(dollars in millions)		Carrying Value			Ownership Percentage	Carrying Value		Ownership Percentage
	USG Boral Building Products (a)		692			50%	N/A		N/A
	Other equity method investments		47			33% - 50%	$	73	33% - 50%
	Total equity method investments		$	739			$	73
	(a)	The carrying value of our investment in UBBP as of September 30, 2014, includes transaction costs of approximately $32 million incurred in the fourth quarter of 2013 and first nine months of 2014.
	Investment in USG Boral Building Products ("UBBP")
	On February 27, 2014, we formed a 50/50 joint venture, USG Boral Building Products ("UBBP"), with Boral Limited ("Boral") and certain of its subsidiaries. UBBP manufactures, distributes and sells certain building products, mines raw gypsum and sells natural and synthetic gypsum throughout Asia, Australasia and the Middle East (the "Territory"). The products that UBBP manufactures and distributes include products for wall, ceiling, floor lining and exterior systems that utilize gypsum, wallboard, referred to as plasterboard in the region, mineral fiber ceiling tiles, steel grid and studs and joint compound.
	On February 27, 2014, as consideration for our 50% ownership in UBBP, we (i) made a cash payment of $513 million to Boral, which includes a $500 million base price and $13 million of customary estimated working capital and net debt adjustments, (ii) contributed to UBBP our subsidiaries and joint venture investments in China, Singapore, India, Malaysia, New Zealand, Australia, the Middle East and Oman, see Note 15, and (iii) granted to UBBP licenses to use certain of our intellectual property rights in the Territory. We funded our cash payment with the net proceeds from our October 2013 issuance of $350 million of 5.875% senior notes and cash on hand. In the event certain performance targets are satisfied by UBBP, we will be obligated to pay Boral scheduled earnout payments in an aggregate amount up to $75 million, comprised first of $25 million based on performance during the first three years after closing and then up to $50 million based on performance during the first five years after closing. In October 2014, we paid an additional $2 million to Boral in conjunction with customary post-closing adjustments.
	We account for our 50% investment in UBBP using the equity method of accounting, and we initially measured its carrying value at cost of approximately $676 million as of February 27, 2014. Our existing wholly-owned subsidiaries and consolidated variable interest entities that were contributed into the joint venture were deconsolidated resulting in a gain of $27 million, which is included in our consolidated statement of operations for the nine months ended September 30, 2014. Approximately $11 million of the gain relates to the remeasurement of our retained investment in the contributed subsidiaries to a preliminary fair value, determined using a discounted cash flow model with several inputs, including a weighted-average discount rate of approximately 11% and a weighted-average long-term growth rate of approximately 2%. Additionally, we recorded a liability of $23 million representing the present value of the first earnout payment, which is included in other liabilities on our accompanying consolidated balance sheet as of September 30, 2014. We are not currently required under applicable accounting guidance to record a liability for the second earnout payment, as such, a liability has not been recorded on our consolidated balance sheet as of September 30, 2014.
	All of our investments accounted for under the equity method are initially recorded at cost, and subsequently adjusted for our share of the net income or loss and cash contributions and distributions to or from these entities.  Because the underlying net assets in our investments are denominated in a foreign currency, translation gains or losses will impact the recorded value of our investment and, for the nine months ended September 30, 2014, resulted in a net loss of $13 million recorded in accumulated other comprehensive income (loss). For the nine months ended September 30, 2014, our accompanying consolidated statement of operations includes $20 million of equity income, representing our share of seven months of results of UBBP of $19 million and our share of income from our other equity method investments of $1 million.
	Summarized financial information for our equity method investments is as follows:
		Three months ended September 30,					Nine months ended September 30,
	(in millions)	2014			2013		2014 (a)		2013
	USG Boral Building Products:
	Net sales	$	286		N/A		$	655	N/A
	Gross profit	77			N/A		179		N/A
	Operating profit	31			N/A		57		N/A
	Net income	25			N/A		42		N/A
	Net income attributable to USG Boral Building Products	24			N/A		39		N/A
	USG share of income from investment accounted for using the equity method	12			N/A		19		N/A
	Other equity method investments(b):
	USG share of income from investments accounted for using the equity method	—			1		1		2
	Total income from equity method investments	12			1		20		2
	(a)	Operating results are presented for UBBP for the seven months ended September 30, 2014.
	(b)	Amounts represent our share of income or loss from all equity method investments, other than UBBP. For the nine months ended September 30, 2014, the amount reflected includes two months of our share of equity method earnings from the joint ventures which we had accounted for as equity method investments prior to being contributed to UBBP on February 27, 2014.

LongLived_Asset_Impairment_Cha

Long-Lived Asset Impairment Charges (Notes)	9 Months Ended
	Sep. 30, 2014
Long-Lived Asset Impairment Charges [Abstract]	'
Long-Lived Asset Impairment Charges	'
	Long-Lived Asset Impairment Charges
	Since we began idling plants in 2007, we have continuously evaluated our manufacturing needs by considering the capacity of existing and idled plants and production lines, as well as capital projects for manufacturing facilities, relative to the demand assumptions included in our long-range plan. Although industry and economic factors have improved and we believe that the overall economic recovery is intact, they are improving at a slower pace than expected, requiring us to reconsider the future utilization of idled plants and production lines, and capital projects for manufacturing facilities. As a result, in the third quarter of 2014, we recorded asset impairment charges totaling $30 million, which includes the following:
	(a) impairment charges of $16 million related to the carrying values of machinery, equipment and buildings at our temporarily idled gypsum quarry and wallboard production facility in Empire, Nevada and at our previously idled and now permanently closed gypsum wallboard line in New Orleans, Louisiana. In addition, in the third quarter 2014 we permanently closed our wallboard line in Detroit, Michigan. No impairment charge was recorded with respect to our wallboard line in Detroit, Michigan, as these assets were previously impaired at the time the plant was originally idled.
	(b) impairment charges of $12 million related to previously incurred and capitalized costs for the construction of two future facilities, which we do not anticipate will be built within our planning horizon.
	(c) impairment charges of $2 million related to the carrying values of machinery, equipment and buildings at our previously idled and now permanently closed paper production line in Gypsum, Ohio.
	The carrying values of the machinery, equipment and buildings at our temporarily idled facility in Empire, Nevada exceeded the estimated future undiscounted cash flows for the remaining useful lives of the assets due to slower than expected acceleration in the markets served by this facility and our forecasts regarding the timing and future rate of recovery in those markets. Based on these conditions, we do not anticipate that the carrying values of the assets at this facility would be recovered prior to end of the assets’ useful lives, and therefore fully impaired these assets in the current period. For the production line in Gypsum, Ohio that we deemed to be permanently closed, we fully impaired the long-lived assets specific to those lines.
	The long-lived asset impairment charges relate solely to our Gypsum segment.

Segments

Segments	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Segments	'
	Segments
	As discussed in Note 1, effective April 1, 2014 we changed the composition of our reportable segments. Prior-year results have been recast to conform with the new presentation of reportable segments. Our operations are organized into four reportable segments: Gypsum (previously North American Gypsum), Ceilings (previously Worldwide Ceilings), Distribution (previously Building Products Distribution) and UBBP. See Note 2 for segment results for UBBP. Segment results for our Gypsum, Distribution and Ceilings segments were as follows:
		Three months ended September 30,						Nine months ended September 30,
	(millions)	2014			2013 (c)			2014(c)			2013 (c)
	Net Sales:
	Gypsum	$	621		$	580		$	1,778		$	1,670
	Ceilings (a)	137			146			392			428
	Distribution	359			331			1,003			931
	Eliminations	(145		)	(132		)	(403		)	(374		)
	Total	$	972		$	925		$	2,770		$	2,655
	Operating Profit (Loss):
	Gypsum (b)	$	12		$	75		$	172		$	188
	Ceilings (a)	30			23			69			77
	Distribution	4			3			9			2
	Corporate	(23		)	(25		)	(65		)	(63		)
	Eliminations	(1		)	(1		)	1			(6		)
	Total	$	22		$	75		$	186		$	198
	(a)	Ceilings' net sales and operating profit for the nine months ended September 30, 2014 includes the results, through February 27, 2014, of our wholly-owned subsidiaries and consolidated joint ventures that were contributed to UBBP.
	(b)	Gypsum's operating profit for both the three and nine months ended September 30, 2014 included a litigation settlement charge of $48 million and long-lived asset impairment charges of $30 million. See Notes 17 and 3, respectively.
	(c)	Net sales and operating profit (loss) have been recast for periods prior to April 1, 2014 to conform with the new presentation of reportable segments.
	In our disclosure of total assets by reportable segment in Note 13 of our Annual Report on Form 10-K for the year ended December 31, 2013, we reflected all cash within Corporate. As part of the consideration for our investment in UBBP on February 27, 2014, we made a cash payment of $513 million to Boral and we contributed to UBBP certain wholly-owned subsidiaries and joint venture investments, collectively the "Contributed Entities." See further discussion in Note 2. Total assets of the Contributed Entities were $139 million, consisting of (a) total assets, net of cash, of our contributed wholly-owned subsidiaries and consolidated joint ventures and (b) our investments in the unconsolidated joint ventures. These assets were included within Worldwide Ceilings, which we now refer to as our Ceilings segment.
	See Note 3 for information related to the long-lived asset impairment charges recorded in our Gypsum segment in the third quarter of 2014.

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	Earnings (Loss) Per Share
	Basic earnings (loss) per share is based on the weighted average number of common shares outstanding. Diluted earnings (loss) per share is based on the weighted average number of common shares outstanding plus the dilutive effect, if any, of market share units, or MSUs, performance shares, restricted stock units, or RSUs, stock options, deferred shares associated with our deferred compensation program for non-employee directors and, for the applicable periods, the potential conversion of our 10% convertible senior notes due 2018, which were converted into common stock in December 2013 and April 2014. See Note 8.
	The reconciliation of basic earnings (loss) per share to diluted earnings (loss) per share is shown in the following table.
		Three months ended September 30,							Nine months ended September 30,
	(millions, except per-share data)	2014				2013			2014			2013
	Income (loss) from continuing operations	$	(11	)		$	24		$	92		$	51
	Less: Net income attributable to noncontrolling interest	1				—			1			—
	Income (loss) from continuing operations attributable to USG	(12		)		24			91			51
	Loss from discontinued operations	—				(1		)	(1		)	(1		)
	Net income (loss) attributable to USG	(12		)		23			90			50
	Effect of dilutive securities - RSUs, MSUs, performance shares and stock options	—				—			—			—
	Effect of dilutive securities - 10% convertible senior notes	—				—			2			—
	Effect of dilutive securities - Deferred compensation program for non-employee directors	—				—			—			—
	Income (loss) available to shareholders	$	(12	)		$	23		$	92		$	50
	Average common shares	144.6				108.6			140.9			108.5
	Dilutive RSUs, MSUs, performance shares and stock options	—				2.4			2.5			2.6
	Common shares issuable upon conversion of our 10% convertible senior notes	—				—			3.5			—
	Deferred shares associated with a deferred compensation program for non-employee directors	—				—			0.2			—
	Average diluted common shares	144.6				111			147.1			111.1
	Earnings (loss) per average common share:
	Income (loss) from continuing operations	$	(0.09	)		$	0.23		$	0.65		$	0.48
	Loss from discontinued operations	—				(0.01		)	(0.01		)	(0.01		)
	Earnings (loss) per average common share	$	(0.09	)		$	0.22		$	0.64		$	0.47
	Diluted earnings (loss) per average common share:
	Income (loss) from continuing operations	$	(0.09	)		$	0.22		$	0.63		$	0.47
	Loss from discontinued operations	—				(0.01		)	(0.01		)	(0.01		)
	Earnings (loss) per average diluted common share	$	(0.09	)		$	0.21		$	0.62		$	0.46
	In December 2013, we converted $325 million of our 10% convertible senior notes due 2018 into approximately 28.5 million common shares. In April 2014, we converted the remaining $75 million of these notes into approximately 6.6 million common shares. See further discussion in Note 8.
	MSUs, performance shares, RSUs, stock options and common shares issuable upon conversion of our 10% convertible senior notes that were not included in the computation of diluted earnings (loss) per share for those periods because their inclusion would be anti-dilutive were as follows:
		Three months ended September 30,						Nine months ended September 30,
	(millions, common shares)	2014			2013			2014		2013
	MSUs, performance shares, RSUs and stock options	5.6			2			2.7		2.2
	10% convertible senior notes due 2018	—			35.1			—		35.1

Marketable_Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2014
Investments, Debt and Equity Securities [Abstract]	'
Marketable Securities	'
	Marketable Securities
	Marketable securities are classified as available-for-sale securities and reported at fair value, with unrealized gains and losses excluded from earnings and reported in accumulated other comprehensive income (loss) on our consolidated balance sheets. Proceeds received from sales and maturities of marketable securities were $166 million for the nine months ended September 30, 2014. Our investments in marketable securities consisted of the following:
		As of September 30, 2014				As of December 31, 2013
	(millions)	Amortized		Fair		Amortized		Fair
		Cost		Value		Cost		Value
	Corporate debt securities	$	60	$	60	$	87	$	87
	U.S. government and agency debt securities	6		6		12		12
	Asset-backed debt securities	13		13		20		20
	Certificates of deposit	15		15		17		17
	Municipal debt securities	6		6		6		6
	Total marketable securities	$	100	$	100	$	142	$	142
	The realized and unrealized gains and losses for the three and nine months ended September 30, 2014 and 2013 were immaterial. Cost basis for securities sold are determined on a first-in-first-out basis.
	Contractual maturities of marketable securities as of September 30, 2014 were as follows:
	(millions)	Amortized		Fair
		Cost		Value
	Due in 1 year or less	$	64	$	64
	Due in 1-5 years	36		36
	Total marketable securities	$	100	$	100
	Actual maturities may differ from the contractual maturities because issuers of the securities may have the right to prepay them.

Intangible_Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Intangible Assets	'
	Intangible Assets
	Intangible assets with definite lives are amortized. These assets are summarized as follows:
		As of September 30, 2014							As of December 31, 2013
	(millions)	Gross		Accumulated			Net		Gross		Accumulated			Net
		Carrying		Amortization					Carrying		Amortization
		Amount							Amount
	Intangible Assets with Definite Lives:
	Customer relationships	$	70	$	(53	)	$	17	$	70	$	(48	)	$	22
	Other	9		(7		)	2		9		(6		)	3
	Total	$	79	$	(60	)	$	19	$	79	$	(54	)	$	25
	Total amortization expense was $2 million and $6 million for the three and nine months ended September 30, 2014 and 2013, respectively. Estimated amortization expense for the remainder of 2014 and for future years is as follows:
	(millions)	2014		2015			2016		2017		2018			2019 and thereafter
	Estimated future amortization expense	$	1	$	7		$	7	$	2	$	1		$	1
	Intangible assets with indefinite lives are not amortized. These assets are summarized as follows:
		As of September 30, 2014							As of December 31, 2013
	(millions)	Gross		Accumulated Impairment Charges			Net		Gross		Accumulated Impairment Charges			Net
		Carrying							Carrying
		Amount							Amount
	Intangible Assets with Indefinite Lives:
	Trade names	$	22	$	—		$	22	$	22	$	—		$	22
	Other	8		1			7		8		1			7
	Total	$	30	$	1		$	29	$	30	$	1		$	29
	Intangible assets are included in other assets on our consolidated balance sheets, except for approximately $5 million of other indefinite-lived intangible assets which met the criteria to be classified as held for sale during the second quarter of 2014 and therefore are included in other current assets on our consolidated balance sheet as of September 30, 2014.

Debt

Debt	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Debt	'
	Debt
	Total debt, including the current portion of long-term debt, consisted of the following:
	(millions)	September 30,		December 31,
		2014		2013
	5.875% senior notes due 2021	$	350	$	350
	6.3% senior notes due 2016	500		500
	7.75% senior notes due 2018, net of discount	500		500
	7.875% senior notes due 2020, net of discount	249		249
	8.375% senior notes due 2018	350		350
	9.75% senior notes due 2014, net of discount	—		59
	10% convertible senior notes due 2018, net of discount	—		72
	Ship mortgage facility (includes $4 million of current portion of long-term debt)	22		25
	Credit facilities of Oman joint ventures	—		11
	Industrial revenue bonds (due 2028 through 2034)	239		239
	Total	$	2,210	$	2,355
	On August 1, 2014, we repaid the remaining of $59 million of principal balance of our 9.75% senior notes due 2014.
	In March 2014, we issued a notice of redemption to redeem the remaining $75 million in aggregate principal amount of outstanding 10% convertible senior notes due 2018. As of March 31, 2014, the notes were recorded on our accompanying consolidated balance sheet at $72 million, net of debt discount of $3 million. The notes could either be (1) redeemed at a stated redemption price or (2) converted into shares of our common stock. The holders of all $75 million in notes called for redemption elected to convert their notes into shares of USG’s common stock. Accordingly, in April 2014, we issued an additional 6,578,946 shares of our common stock in connection with the conversion of the notes.
	Our U.S. credit facility contains a single financial covenant that would require us to maintain a minimum fixed charge coverage ratio of no less than 1.1-to-1.0 if and for so long as the excess of the borrowing base over the outstanding borrowings under the credit agreement is less than the greater of (a) $40 million and (b) 15% of the lesser of (i) the aggregate revolving commitments at such time and (ii) the borrowing base at such time. As of September 30, 2014, our fixed charge coverage ratio was 1.14-to-1.0. Because we currently satisfy the required fixed charge coverage ratio, we are not required to maintain a minimum borrowing availability under the credit facility. Taking into account the most recent borrowing base calculation delivered under the credit facility, which reflects trade receivables and inventory as of September 30, 2014, and outstanding letters of credit of $54 million as of September 30, 2014, borrowings available under the credit facility were approximately $311 million. As of September 30, 2014 and during the quarter then-ended, there were no borrowings under the facility.
	On April 17, 2014, we entered into Amendment No. 1 (the “Amendment”) to our U.S. credit facility. The Amendment, among other things, (i) deleted the provisions providing for an early maturity date in the event we either (1) have not repaid or provided for the repayment of our outstanding 9.75% senior notes due 2014 (the “2014 Notes”) by May 2, 2014 or (2) did not have at least $500 million in liquidity from May 2, 2014 until the repayment of the 2014 Notes, and (ii) revised the definition of borrowing base to add an additional reserve against the borrowing base in the amount of the unpaid principal balance of the 2014 Notes outstanding from time to time.
	During the nine months ended September 30, 2014, there was an immaterial amount of borrowings outstanding under our Canadian credit agreement and no borrowings outstanding as of September 30, 2014. The U.S. dollar equivalent of borrowings available under this agreement as of September 30, 2014 was $35 million. On October 22, 2014, in connection with the amendment and restatement of our credit facility described below, we terminated our Canadian credit facility.
	In June 2013, our joint ventures in Oman, which were fully consolidated at that time, each entered into separate secured credit agreements, which were guaranteed by us and our joint venture partner.  As of December 31, 2013, there was $11 million in outstanding term loan borrowings under the credit agreements. During the first two months of 2014, an additional $3 million of term loans were borrowed under these agreements. In connection with our investment in UBBP on February 27, 2014, we contributed our joint ventures in Oman, and the corresponding credit facilities, to UBBP. See further description of our investment in UBBP in Note 2.
	The fair value of our debt was approximately $2.362 billion as of September 30, 2014 and $2.659 billion as of December 31, 2013. The fair values were based on quoted prices for identical or similar liabilities in markets that are not active or valuation models in which all significant inputs and value drivers are observable and, as a result, are classified as Level 2 inputs. See Note 10 for further discussion on fair value measurements and classifications.
	As of September 30, 2014, we were in compliance with the covenants contained in our credit facilities.
	AMENDED AND RESTATED CREDIT FACILITY
	On October 22, 2014, we amended and restated our credit facility in order to, among other things, join CGC, Inc., or CGC, as a party and to increase the maximum borrowing limit under the credit agreement from $400 million to $450 million (including a $50 million borrowing sublimit for CGC). As amended and restated, the credit agreement allows for the borrowing of revolving loans and issuance of letters of credit (up to a maximum of $200 million at any time outstanding, in aggregate) to USG and its subsidiaries. Pursuant to the credit agreement, the maximum principal amount of revolving loans and letters of credit that may be borrowed by and/or be issued in favor USG and CGC at any time may fluctuate based upon two separate borrowing base calculations.
	USG's obligations under the credit facility are guaranteed by USG and its significant domestic subsidiaries and secured by their and USG’s trade receivables and inventory. CGC's obligation's under the credit facility are secured by trade receivables and inventory of certain subsidiaries. The credit facility matures on October 22, 2019 unless terminated earlier in accordance with its terms. The credit facility is available to fund working capital needs and for other general corporate purposes..
	The credit agreement contains a financial covenant that would require us to maintain a minimum fixed charge coverage ratio of not less than 1.0 to 1.0 if availability (as defined in the credit agreement) is less than an amount equal to 10% of the lesser of (a) the aggregate revolving commitment at such time and (b) the aggregate borrowing base at such time. We would be required to continue to comply with such financial covenant until availability under the credit agreement exceeds such minimum threshold for 30 consecutive calendar days thereafter.

Derivative_Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments	'
	Derivative Instruments
	We use derivative instruments to manage selected commodity price and foreign currency exposures as described below. We do not use derivative instruments for speculative trading purposes, and we typically do not hedge beyond two years. Cash flows from derivative instruments are included in net cash provided by operating activities in the consolidated statements of cash flows.
	COMMODITY DERIVATIVE INSTRUMENTS
	As of September 30, 2014, we had 22 million mmBTUs (millions of British Thermal Units) in aggregate notional amount of outstanding natural gas swap and option contracts to hedge forecasted purchases. All of these contracts mature by December 31, 2016. For contracts designated as cash flow hedges, the net unrealized loss that remained in accumulated other comprehensive income (loss), or AOCI, as of September 30, 2014 was $3 million. No ineffectiveness was recorded on contracts designated as cash flow hedges in the first nine months of 2014. Gains and losses on contracts designated as cash flow hedges are reclassified into earnings when the underlying forecasted transactions affect earnings. For contracts designated as cash flow hedges, we reassess the probability of the underlying forecasted transactions occurring on a quarterly basis. Changes in fair value on contracts not designated as cash flow hedges are recorded to earnings. The fair value of those contracts not designated as cash flow hedges was an immaterial unrealized gain as of September 30, 2014.
	FOREIGN EXCHANGE DERIVATIVE INSTRUMENTS
	We have foreign exchange forward contracts to hedge forecasted purchases of products and services denominated in foreign currencies. The notional amount of these contracts was $69 million as of September 30, 2014, and they mature by June 30, 2016. These forward contracts are designated as cash flow hedges and no ineffectiveness was recorded in the first nine months of 2014. Gains and losses on the contracts are reclassified into earnings when the underlying transactions affect earnings. The fair value of these contracts that remained in AOCI was a $2 million unrealized gain as of September 30, 2014.
	COUNTERPARTY RISK, MASTER NETTING ARRANGEMENTS AND BALANCE SHEET OFFSETTING
	We are exposed to credit losses in the event of nonperformance by the counterparties to our derivative instruments. As of September 30, 2014, our derivatives were in a $1 million net liability position. All of our counterparties have investment grade credit ratings; accordingly, we anticipate that they will be able to fully satisfy their obligations under the contracts.
	Our derivative contracts are governed by master netting agreements negotiated between us and the counterparties that reduce our counterparty credit exposure. The agreements outline the conditions (such as credit ratings and net derivative fair values) upon which we, or the counterparties, are required to post collateral. As of September 30, 2014, we had $6 million of collateral posted with our counterparties related to our derivatives.
	We have not adopted an accounting policy to offset fair value amounts related to derivative contracts under our master netting arrangements; therefore, individual derivative contracts are reflected on a gross basis, as either assets or liabilities, on our consolidated balance sheets, based on their fair value as of the balance sheet date.
	FINANCIAL STATEMENT INFORMATION
	The following are the pretax effects of derivative instruments on the consolidated statements of operations for the three months ended September 30, 2014 and 2013.
		Amount of Gain or (Loss)								Location of Gain or (Loss)		Amount of Gain or (Loss) Reclassified from
		Recognized in								Reclassified from		AOCI into Income
		Other Comprehensive Income on Derivatives (Effective Portion)								AOCI into Income		(Effective Portion)
										(Effective Portion)
	(millions)	2014				2013						2014		2013
	Derivatives in Cash Flow Hedging Relationships
	Commodity contracts	$	(3	)		$	(1	)		Cost of products sold		$	—	$	—
	Foreign exchange contracts	3				(1		)		Cost of products sold		1		1
	Total	$	—			$	(2	)				$	1	$	1
			Location of Gain or (Loss)		Amount of Gain or (Loss) Recognized in Income
			Recognized in Income		on Derivatives
			on Derivatives
	(millions)				2014				2013
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts		Cost of products sold		$	(1	)		$	—
	Total				$	(1	)		$	—
	The following are the pretax effects of derivative instruments on the consolidated statements of operations for the nine months ended September 30, 2014 and 2013.
		Amount of Gain or (Loss)								Location of Gain or (Loss)		Amount of Gain or (Loss) Reclassified from
		Recognized in								Reclassified from		AOCI into Income
		Other Comprehensive Income on Derivatives (Effective Portion)								AOCI into Income		(Effective Portion)
										(Effective Portion)
	(millions)	2014				2013						2014		2013
	Derivatives in Cash Flow Hedging Relationships
	Commodity contracts	$	(1	)		$	(1	)		Cost of products sold		$	2	$	(1	)
	Foreign exchange contracts	3				2				Cost of products sold		2		2
	Total	$	2			$	1					$	4	$	1
			Location of Gain or (Loss)		Amount of Gain or (Loss) Recognized in Income
			Recognized in Income		on Derivatives
			on Derivatives
	(millions)				2014				2013
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts		Cost of products sold		$	—			$	1
	Total				$	—			$	1
	The following are the fair values of derivative instruments and the location on our consolidated balance sheets as of September 30, 2014 and December 31, 2013.
		Balance Sheet	Fair Value								Balance Sheet	Fair Value
		Location									Location
	(millions)		9/30/14				12/31/13					9/30/14		12/31/13
	Derivatives in Cash Flow Hedging Relationships
	Commodity contracts	Other current assets	$	2			$	2			Accrued expenses	$	4	$	—
	Commodity contracts	Other assets	—				—				Other liabilities	1		—
	Foreign exchange contracts	Other current assets	1				1				Accrued expenses	—		—
	Foreign exchange contracts	Other assets	1				—				Other liabilities	—		—
	Total derivatives in cash flow hedging relationships		$	4			$	3				$	5	$	—
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts	Other current assets	$	1			$	2			Accrued expenses	$	1	$	—
	Total derivatives not designated as hedging instruments		$	1			$	2				$	1	$	—
	Total derivatives	Total assets	$	5			$	5			Total liabilities	$	6	$	—
	As of September 30, 2014, we had no derivatives designated as fair value hedges or net investment hedges.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	Certain assets and liabilities are required to be recorded at fair value. There are three levels of inputs that may be used to measure fair value. Level 1 is defined as quoted prices for identical assets and liabilities in active markets. Level 2 is defined as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets. Level 3 is defined as valuations derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable. Certain assets and liabilities are measured at fair value on a nonrecurring basis rather than on an ongoing basis, such as when there is evidence of impairment or when a new liability is being established that requires fair value measurement.
	The cash equivalents shown in the table below primarily consist of money market funds that are valued based on quoted prices in active markets and as a result are classified as Level 1. We use quoted prices, other readily observable market data and internally developed valuation models when valuing our derivatives and marketable securities and have classified them as Level 2. Derivatives are valued using the income approach including discounted-cash-flow models or a Black-Scholes option pricing model and readily observable market data. The inputs for the valuation models are obtained from data providers and include end-of-period spot and forward natural gas prices, foreign currency exchange rates, natural gas price volatility and LIBOR and swap rates for discounting the cash flows implied from the derivative contracts. Marketable securities are valued using income and market value approaches and values are based on quoted prices or other observable market inputs received from data providers. The valuation process may include pricing matrices, or prices based upon yields, credit spreads or prices of securities of comparable quality, coupon, maturity and type.
	Our assets and liabilities measured at fair value on a recurring basis were as follows:
		Quoted Prices				Significant					Significant				Total
		in Active				Other					Unobservable
		Markets for				Observable					Inputs
		Identical				Inputs					(Level 3)
		Assets				(Level 2)
		(Level 1)
	(millions)	9/30/14		12/31/13		9/30/14			12/31/13		9/30/14		12/31/13		9/30/14			12/31/13
	Cash equivalents	$	133	$	549	$	13		$	24	$	—	$	—	$	146		$	573
	Marketable securities:
	Corporate debt securities	—		—		60			87		—		—		60			87
	U.S. government and agency debt securities	—		—		6			12		—		—		6			12
	Asset-backed debt securities	—		—		13			20		—		—		13			20
	Certificates of deposit	—		—		15			17		—		—		15			17
	Municipal debt securities	—		—		6			6		—		—		6			6
	Derivative assets	—		—		5			5		—		—		5			5
	Derivative liabilities	—		—		(6		)	—		—		—		(6		)	—
	During the third quarter of 2014, we reviewed our property, plant and equipment for potential impairment by comparing the carrying values of those assets with their fair values as estimated using the future undiscounted cash flows for their remaining useful lives. As disclosed in Note 3, we recorded long-lived asset impairment charges of $30 million for third quarter of 2014. We measured the fair value of the machinery, equipment and buildings as of September 30, 2014 using measurements classified as Level 3.

Employee_Retirement_Plans

Employee Retirement Plans	9 Months Ended
	Sep. 30, 2014
Compensation and Retirement Disclosure [Abstract]	'
Employee Retirement Plans	'
	Employee Retirement Plans
	The components of net pension and postretirement benefits costs are summarized in the following table:
		Three months ended September 30,						Nine months ended September 30,
	(millions)	2014			2013			2014			2013
	Pension:
	Service cost of benefits earned	$	9		$	10		$	27		$	29
	Interest cost on projected benefit obligation	16			16			49			47
	Expected return on plan assets	(20		)	(19		)	(60		)	(57		)
	Net amortization	7			11			19			34
	Net pension cost	$	12		$	18		$	35		$	53
	Postretirement:
	Service cost of benefits earned	$	1		$	1		$	2		$	3
	Interest cost on projected benefit obligation	1			2			5			5
	Net amortization	(8		)	(9		)	(26		)	(26		)
	Net postretirement benefit	$	(6	)	$	(6	)	$	(19	)	$	(18	)
	During the first nine months of 2014, we made cash contributions of $50 million to the USG Corporation Retirement Plan Trust, $8 million to our pension plan in Canada, and $2 million, in aggregate, to certain other domestic and foreign pension plans. We expect to make total contributions to our pension plans in 2014 of approximately $61 million.
	In April 2014, we amended our U.S. postretirement benefit plan for those retiree medical plan participants who are pre-65 retirees, to defer the effective date that requires participants to begin purchasing individual coverage in the Affordable Insurance Exchanges or individual Medicare marketplace using a company-funded subsidy from January 1, 2015 to January 1, 2016. The financial statement impact of the plan amendment was immaterial.
	In the fourth quarter of 2014, we expect to incur a settlement charge between $12 million and $14 million with respect to an early pension settlement for USG (U.K.) Ltd.’s pension plan that was previously frozen to permanently eliminate future benefit accruals. The settlement charge will be calculated on the day the annuity purchase occurs.

ShareBased_Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share-Based Compensation	'
	Share-Based Compensation
	During the first nine months of 2014, we granted share-based compensation in the form of market share units, or MSUs, performance shares, and restricted stock units, or RSUs, to eligible participants under our Long-Term Incentive Plan. We recognize expense on all share-based grants over the service period, which is the shorter of the period until the employees’ retirement eligibility dates and the service period of the award for awards expected to vest. Expense is generally reduced for estimated forfeitures. Awards granted during the first nine months of 2014 and assumptions used to determine fair value were as follows:
		MSUs			Performance Shares			RSUs
	Awards granted	364,180			111,287			57,500
	Weighted average fair value	$	40.2		$	46.46		$	33.37
	Expected volatility	54.93		%	54.93		%	N/A
	Risk-free rate (a)	0.63		%	0.63		%	N/A
	Expected term (in years) (b)	2.94			2.94			N/A
	Expected dividends	—			—			N/A
	(a)	The risk-free rate was based on zero coupon U.S. government issues at the time of grant.
	(b)	The expected term represents the period from the valuation date to the end of the performance period.
	MARKET SHARE UNITS
	The MSUs granted during the first nine months of 2014 generally vest after a three-year period based on our actual stock price performance during such period. The number of MSUs earned will vary from zero to 150% of the number of MSUs awarded depending on the actual performance of our stock price. In the case of termination of employment due to death, disability or retirement during the performance period, vesting will be pro-rated based on the number of full months employed in 2014. Awards earned will be issued at the end of the three-year period. MSUs may vest earlier in the case of a change in control in most circumstances only if there is also a related loss of employment or diminution of duties. Each MSU earned will be settled in common stock.
	We estimated the fair value of each MSU granted on the date of grant using a Monte Carlo simulation that used the assumptions noted in the table above. Volatility was based on stock price history immediately prior to grant for a period commensurate with the remaining life of the plan.
	PERFORMANCE SHARES
	The performance shares granted during the first nine months of 2014 generally vest after a three-year period based on our total stockholder return relative to the performance of the Dow Jones U.S. Construction and Materials Index, with adjustments to that index in certain circumstances, for the three-year period. The number of performance shares earned will vary from zero to 200% of the number awarded depending on that relative performance. Generally, vesting will be pro-rated based on the number of full months employed during the performance period in the case of death, disability, or retirement, and pro-rated awards earned will be issued at the end of the three-year period. Each performance share earned will be settled in common stock.
	We estimated the fair value of each performance share granted on the date of grant using a Monte Carlo simulation that used the assumptions noted in the table above. Expected volatility was based on implied volatility of our traded options and the daily historical volatilities of our peer group.
	RESTRICTED STOCK UNITS
	The RSUs granted during the first nine months of 2014 vest after a specified number of years from the date of grant or at a specified date. Generally, RSUs may vest earlier in the case of death, disability, retirement or a change in control, provided that RSUs granted after 2012 will vest upon a change in control in most circumstances only if there is also a related loss of employment or diminution of duties. Each RSU is settled in a share of our common stock after the vesting period. The fair value of each RSU granted is equal to the closing price of our common stock on the date of grant.

Supplemental_Balance_Sheet_Inf

Supplemental Balance Sheet Information	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Supplemental Balance Sheet Information	'
	Supplemental Balance Sheet Information
	INVENTORIES
	Total inventories consisted of the following:
	(millions)	30-Sep-14			31-Dec-13
	Finished goods and work in progress	$	264		$	270
	Raw materials	62			62
	Total	$	326		$	332
	ASSET RETIREMENT OBLIGATIONS
	Changes in the liability for asset retirement obligations consisted of the following:
		Nine months ended September 30,
	(millions)	2014			2013
	Balance as of January 1	$	132		$	139
	Accretion expense	6			5
	Liabilities incurred	1			2
	Changes in estimated cash flows (a)	(13		)	(11		)
	Liabilities settled	(2		)	(1		)
	Foreign currency translation	(2		)	(2		)
	Balance as of September 30	$	122		$	132
	(a)	Changes in estimated cash flows for the nine months ended September 30, 2014 includes changes in estimates primarily related to reclamation activities for our gypsum quarry and ship loading facility in Windsor, Nova Scotia, Canada, which we permanently closed during the third quarter of 2011, and our mining operation in Little Narrows, Nova Scotia, Canada.
	ACCRUED INTEREST
	Interest accrued on our debt as of both September 30, 2014 and December 31, 2013 was $48 million and is included in accrued expenses on our consolidated balance sheets.
	ASSETS HELD FOR SALE
	In June 2014, we sold surplus property for a gain of $12 million which is included in cost of goods sold in our statement of operations. The asset was classified as held for sale in our consolidated balance sheet at December 31, 2013 with a carrying value of approximately zero. Assets held for sale as of September 30, 2014 include approximately $5 million of indefinite-lived intangible assets which are classified as other current assets in our accompanying consolidated balance sheet.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Accumulated Other Comprehensive Income (Loss)	'
	Accumulated Other Comprehensive Income (Loss)
	Changes in the balances of each component of AOCI for the nine months ended September 30, 2014 and 2013 were as follows:
		Derivatives							Defined Benefit Plans								Foreign						AOCI
																	Currency Translation
	(millions)	2014			2013				2014				2013				2014			2013			2014			2013
	Balance as of January 1	$	35		$	32			$	(32	)		$	(303	)		$	21		$	38		$	24		$	(233	)
	Other comprehensive income (loss) before reclassifications, net of tax	1			—				(6		)		(15		)		(28		)	(12		)	(33		)	(27		)
	Less: Amounts reclassified from AOCI, net of tax	4			—				9				(8		)		5			—			18			(8		)
	Net other comprehensive income (loss)	(3		)	—				(15		)		(7		)		(33		)	(12		)	(51		)	(19		)
	Balance as of September 30	$	32		$	32			$	(47	)		$	(310	)		$	(12	)	$	26		$	(27	)	$	(252	)
	Amounts reclassified from AOCI, net of tax, for the three months and nine months ended September 30, 2014 and 2013, were as follows:
			Three months ended September 30,							Nine months ended September 30,
			2014			2013				2014				2013
	Derivatives
	Net reclassification from AOCI for cash flow hedges included in cost of products sold		$	1		$	1			$	4			$	1
	Income tax expense on reclassification from AOCI included in income tax expense (benefit)		—			(1		)		—				(1		)
	Net amount reclassified from AOCI		$	1		$	—			$	4			$	—
	Defined Benefit Plans
	Net reclassification from AOCI for amortization of prior service cost included in cost of products sold		$	2		$	(2	)		$	5			$	(7	)
	Net reclassification from AOCI for amortization of prior service cost included in selling and administrative expenses		1			(1		)		3				(2		)
	Income tax expense on reclassification from AOCI included in income tax expense (benefit)		—			—				(1		)		1
	Net amount reclassified from AOCI		$	3		$	(3	)		$	9			$	(8	)
	Foreign Currency Translation
	Net reclassification from AOCI for translation gains realized upon the deconsolidation of foreign subsidiaries included in selling and administrative expenses		$	—		$	—			$	5			$	—
	Income tax expense on reclassification from AOCI included in income tax expense (benefit)		—			—				—				—
	Net amount reclassified from AOCI		$	—		$	—			$	5			$	—
	We estimate that we will reclassify a net $1 million after-tax loss on derivatives from AOCI to earnings within the next 12 months.

Oman_Investment

Oman Investment	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Oman Investment	'
	Oman Investment
	In June of 2012, we entered into a strategic partnership with the Zawawi Group in Oman to establish a mining operation by acquiring 55% of Zawawi Gypsum LLC, or ZGL, which holds the mining rights to a gypsum quarry in Salalah, Oman. Quarry mining operations commenced in October 2013. The second phase of the partnership is a 50/50 manufacturing venture, USG-Zawawi Drywall LLC, or ZDL, to build and operate a low cost wallboard plant in Oman. Wallboard production operations are expected to commence by the end of 2014.
	We accounted for the acquisition of the mining rights as an asset acquisition and measured our interest in the mining rights at our cost. The mining rights are depleted based upon tonnage mined relative to the total probable capacity in the quarry, and are presented within total property, plant and equipment in our accompanying consolidated balance sheet as of December 31, 2013. We determined that both entities were variable interest entities (VIEs), and, as such, we consolidated the VIEs through February 27, 2014 when our interests in ZGL and ZDL were contributed to UBBP. See Note 2.
	As of December 31, 2013, other liabilities included approximately $8 million of loans payable and the related accrued interest due to the joint venture partner. We contributed our Oman joint ventures, including these loans, to UBBP on February 27, 2014; therefore, the loans payable are no longer reflected on our balance sheet as of September 30, 2014. Also as a result of our contribution of our Oman joint ventures to UBBP, non-controlling interest within shareholders' equity decreased by approximately $24 million.
	See Note 8 for a description of the credit facilities entered into by our joint ventures in Oman in June 2013.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	In the third quarter of 2014, we had income tax expense of approximately $2 million from foreign, state and local jurisdictions. In the United States, we are in a net operating loss carryforward position and our deferred income tax assets are subject to a valuation allowance. Therefore, any income or loss before income taxes does not generate a corresponding income tax expense or benefit. Income tax expense in the current quarter reflects income taxes for certain foreign, state and local jurisdictions.
	For the first nine months of 2014, we had income tax expense of $7 million, which primarily reflects income taxes for certain foreign, state and local jurisdictions, including approximately $1 million of withholding taxes on property contributed to UBBP. See Note 2.
	In assessing the requirement for, and amount of, a valuation allowance in accordance with the more-likely-than-not standard, we give appropriate consideration to all positive and negative evidence related to the realization of the deferred tax assets. As of September 30, 2014, we had federal net operating loss, or NOL, carryforwards of approximately $1.993 billion that are available to offset future federal taxable income and will expire in the years 2026 through 2033, none of which are subject to Internal Revenue Code limitations under Section 382. In addition, as of that date, we had federal AMT credit carryforwards of approximately $45 million that are available to reduce future regular federal income taxes over an indefinite period. In order to fully realize these U.S. federal net deferred tax assets, taxable income of approximately $2.122 billion would need to be generated during the period before their expiration. In addition, we have federal foreign tax credit carryforwards of $8 million that will expire in 2015.
	As of September 30, 2014, we had a gross deferred tax asset related to our state NOLs and tax credit carryforwards of $269 million, of which $11 million will expire in 2014. The remainder will expire if unused in years 2015 through 2033. We also had NOL and tax credit carryforwards in various foreign jurisdictions in the amount of $2 million as of September 30, 2014, against which we have maintained a valuation allowance.
	During periods prior to 2014, we established a valuation allowance against our deferred tax assets totaling $995 million. During the first nine months of 2014, we recorded a decrease in the valuation allowance against our deferred tax assets of $34 million. Approximately $11 million of the decrease related to the realizability of our deferred tax assets due to state law changes. The other $23 million of the decrease resulted from a reduction in the gross value of our deferred tax assets. As a result of both decreases, and based upon an evaluation of all available evidence, we recorded corresponding reductions in the valuation allowance, resulting in no net impact to our consolidated statement of operations. The decreases in the valuation allowance in 2014 resulted in a deferred tax asset valuation allowance of $961 million as of September 30, 2014.
	The Internal Revenue Code imposes limitations on a corporation’s ability to utilize NOLs if it experiences an “ownership change.” In general terms, an ownership change may result from transactions increasing the ownership of certain stockholders in the stock of a corporation by more than 50 percentage points over a three-year period. If we were to experience an ownership change, utilization of our NOLs would be subject to an annual limitation determined by multiplying the market value of our outstanding shares of stock at the time of the ownership change by the applicable long-term tax-exempt rate, which was 3.06% for September 2014. Any unused annual limitation may be carried over to later years within the allowed NOL carryforward period. The amount of the limitation may, under certain circumstances, be increased or decreased by built-in gains or losses held by us at the time of the change that are recognized in the five-year period after the change. Many states have similar limitations. If an ownership change had occurred as of September 30, 2014, our annual U.S. federal NOL utilization would have been limited to approximately $122 million per year.

Litigation

Litigation	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Litigation	'
	Litigation
	WALLBOARD PRICING CLASS ACTION LAWSUITS
	In late 2012, USG Corporation and United States Gypsum Company were named as defendants in putative class action lawsuits alleging that since at least September 2011, U.S. wallboard manufacturers conspired to fix and raise the price of gypsum wallboard sold in the United States and to effectuate the alleged conspiracy by ending the practice of providing job quotes on wallboard. These lawsuits are consolidated for pretrial proceedings in multi-district litigation in the United States District Court for the Eastern District of Pennsylvania, under the title In re: Domestic Drywall Antitrust Litigation, MDL No. 2437. One group of plaintiffs purports to represent a class of entities that purchased gypsum wallboard in the United States directly from any of the defendants or their affiliates from January 1, 2012 to the present. The second group of plaintiffs purports to bring their claims and seek damages on behalf of indirect purchasers of gypsum wallboard. These indirect purchaser plaintiffs seek to certify a separate class of persons or entities who from January 1, 2012 through the present indirectly purchased wallboard in the United States from the defendants or their affiliates for end use and not for resale.
	In the fall of 2013, similar lawsuits were filed in Quebec and Ontario courts on behalf of purchasers of wallboard in Canada. These Canadian lawsuits also name as defendants CGC,as well as other Canadian and U.S. wallboard manufacturers.
	USG has denied the allegations made in these wallboard pricing lawsuits, believes these cases are without merit, and that USG’s actions were at all times lawful. U.S. antitrust litigation, however, is expensive and protracted, with inherent risks and uncertainties, including the potential of triple damages and joint and several liability. To avoid these expenses, risks and further distraction of management, in October 2014, we entered into a settlement agreement in principle with the attorneys representing the direct and indirect purchaser plaintiffs in the U.S. wallboard pricing lawsuits. Pursuant to the settlement in principle, which is subject to finalization of a settlement agreement and court approval, USG will pay a total of $48 million to resolve the U.S. direct and indirect purchaser cases. Accordingly we have recorded a $48 million charge in the third quarter of 2014 related to this settlement.  If we are unable to settle the U.S. litigation under the terms currently contemplated, or at all, there can be no assurance that the outcome of these lawsuits will not have a material effect on our business, financial condition, operating results or cash flows.
	The settlement described above does not include the Canadian lawsuits. At this stage of the Canadian lawsuits, we are not able to estimate the amount, if any, of any reasonably possible loss or range of reasonably possible losses. We believe, however, that these Canadian lawsuits will not have a material effect on our results of operations, financial position, or cash flows.
	ENVIRONMENTAL LITIGATION
	We have been notified by state and federal environmental protection agencies of possible involvement as one of numerous “potentially responsible parties” in a number of Superfund sites in the United States. As a potentially responsible party, we may be responsible to pay for some part of the cleanup of hazardous waste at those sites. In most of these sites, our involvement is expected to be minimal. In addition, we are involved in environmental cleanups of other property that we own or owned. As of September 30, 2014 and December 31, 2013, we had an accrual of $16 million and $18 million, respectively, for our probable and reasonably estimable liability in connection with these matters. Our accruals take into account all known or estimated undiscounted costs associated with these sites, including site investigations and feasibility costs, site cleanup and remediation, certain legal costs, and fines and penalties, if any. However, we continue to review these accruals as additional information becomes available and revise them as appropriate. Based on the information known to us, we believe these environmental matters will not have a material effect on our results of operations, financial position or cash flows.
	OTHER LITIGATION
	We are named as defendants in other claims and lawsuits arising from our operations, including claims and lawsuits arising from the operation of our vehicles, product performance or warranties, personal injury and commercial disputes. We believe that we have properly accrued for our probable liability in connection with these claims and suits, taking into account the probability of liability, whether our exposure can be reasonably estimated and, if so, our estimate of our liability or the range of our liability. We do not expect these or any other litigation matters involving USG to have a material effect on our results of operations, financial position or cash flows.

Equity_Method_Investments_Tabl

Equity Method Investments (Tables)	9 Months Ended
	Sep. 30, 2014
Equity Method Investments and Joint Ventures [Abstract]	'
Equity Method Investments	'
	Equity method investments as of September 30, 2014 and December 31, 2013, were as follows:
			30-Sep-14				31-Dec-13
	(dollars in millions)		Carrying Value			Ownership Percentage	Carrying Value		Ownership Percentage
	USG Boral Building Products (a)		692			50%	N/A		N/A
	Other equity method investments		47			33% - 50%	$	73	33% - 50%
	Total equity method investments		$	739			$	73
	(a)	The carrying value of our investment in UBBP as of September 30, 2014, includes transaction costs of approximately $32 million incurred in the fourth quarter of 2013 and first nine months of 2014.
	Summarized financial information for our equity method investments is as follows:
		Three months ended September 30,					Nine months ended September 30,
	(in millions)	2014			2013		2014 (a)		2013
	USG Boral Building Products:
	Net sales	$	286		N/A		$	655	N/A
	Gross profit	77			N/A		179		N/A
	Operating profit	31			N/A		57		N/A
	Net income	25			N/A		42		N/A
	Net income attributable to USG Boral Building Products	24			N/A		39		N/A
	USG share of income from investment accounted for using the equity method	12			N/A		19		N/A
	Other equity method investments(b):
	USG share of income from investments accounted for using the equity method	—			1		1		2
	Total income from equity method investments	12			1		20		2
	(a)	Operating results are presented for UBBP for the seven months ended September 30, 2014.
	(b)	Amounts represent our share of income or loss from all equity method investments, other than UBBP. For the nine months ended September 30, 2014, the amount reflected includes two months of our share of equity method earnings from the joint ventures which we had accounted for as equity method investments prior to being contributed to UBBP on February 27, 2014.

Segments_Tables

Segments (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Net sales and operating profit (loss) by segment	'
	Segment results for our Gypsum, Distribution and Ceilings segments were as follows:
		Three months ended September 30,						Nine months ended September 30,
	(millions)	2014			2013 (c)			2014(c)			2013 (c)
	Net Sales:
	Gypsum	$	621		$	580		$	1,778		$	1,670
	Ceilings (a)	137			146			392			428
	Distribution	359			331			1,003			931
	Eliminations	(145		)	(132		)	(403		)	(374		)
	Total	$	972		$	925		$	2,770		$	2,655
	Operating Profit (Loss):
	Gypsum (b)	$	12		$	75		$	172		$	188
	Ceilings (a)	30			23			69			77
	Distribution	4			3			9			2
	Corporate	(23		)	(25		)	(65		)	(63		)
	Eliminations	(1		)	(1		)	1			(6		)
	Total	$	22		$	75		$	186		$	198
	(a)	Ceilings' net sales and operating profit for the nine months ended September 30, 2014 includes the results, through February 27, 2014, of our wholly-owned subsidiaries and consolidated joint ventures that were contributed to UBBP.
	(b)	Gypsum's operating profit for both the three and nine months ended September 30, 2014 included a litigation settlement charge of $48 million and long-lived asset impairment charges of $30 million. See Notes 17 and 3, respectively.
	(c)	Net sales and operating profit (loss) have been recast for periods prior to April 1, 2014 to conform with the new presentation of reportable segments.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Reconciliation of basic earnings per share to diluted earnings per share	'
	The reconciliation of basic earnings (loss) per share to diluted earnings (loss) per share is shown in the following table.
		Three months ended September 30,							Nine months ended September 30,
	(millions, except per-share data)	2014				2013			2014			2013
	Income (loss) from continuing operations	$	(11	)		$	24		$	92		$	51
	Less: Net income attributable to noncontrolling interest	1				—			1			—
	Income (loss) from continuing operations attributable to USG	(12		)		24			91			51
	Loss from discontinued operations	—				(1		)	(1		)	(1		)
	Net income (loss) attributable to USG	(12		)		23			90			50
	Effect of dilutive securities - RSUs, MSUs, performance shares and stock options	—				—			—			—
	Effect of dilutive securities - 10% convertible senior notes	—				—			2			—
	Effect of dilutive securities - Deferred compensation program for non-employee directors	—				—			—			—
	Income (loss) available to shareholders	$	(12	)		$	23		$	92		$	50
	Average common shares	144.6				108.6			140.9			108.5
	Dilutive RSUs, MSUs, performance shares and stock options	—				2.4			2.5			2.6
	Common shares issuable upon conversion of our 10% convertible senior notes	—				—			3.5			—
	Deferred shares associated with a deferred compensation program for non-employee directors	—				—			0.2			—
	Average diluted common shares	144.6				111			147.1			111.1
	Earnings (loss) per average common share:
	Income (loss) from continuing operations	$	(0.09	)		$	0.23		$	0.65		$	0.48
	Loss from discontinued operations	—				(0.01		)	(0.01		)	(0.01		)
	Earnings (loss) per average common share	$	(0.09	)		$	0.22		$	0.64		$	0.47
	Diluted earnings (loss) per average common share:
	Income (loss) from continuing operations	$	(0.09	)		$	0.22		$	0.63		$	0.47
	Loss from discontinued operations	—				(0.01		)	(0.01		)	(0.01		)
	Earnings (loss) per average diluted common share	$	(0.09	)		$	0.21		$	0.62		$	0.46
Schedule of anti-dilutive securities excluded from computation of earnings per share	'
	MSUs, performance shares, RSUs, stock options and common shares issuable upon conversion of our 10% convertible senior notes that were not included in the computation of diluted earnings (loss) per share for those periods because their inclusion would be anti-dilutive were as follows:
		Three months ended September 30,						Nine months ended September 30,
	(millions, common shares)	2014			2013			2014		2013
	MSUs, performance shares, RSUs and stock options	5.6			2			2.7		2.2
	10% convertible senior notes due 2018	—			35.1			—		35.1

Marketable_Securities_Tables

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2014
Investments, Debt and Equity Securities [Abstract]	'
Investments in marketable securities	'
	Our investments in marketable securities consisted of the following:
		As of September 30, 2014				As of December 31, 2013
	(millions)	Amortized		Fair		Amortized		Fair
		Cost		Value		Cost		Value
	Corporate debt securities	$	60	$	60	$	87	$	87
	U.S. government and agency debt securities	6		6		12		12
	Asset-backed debt securities	13		13		20		20
	Certificates of deposit	15		15		17		17
	Municipal debt securities	6		6		6		6
	Total marketable securities	$	100	$	100	$	142	$	142
Contractual maturities of marketable securities	'
	Contractual maturities of marketable securities as of September 30, 2014 were as follows:
	(millions)	Amortized		Fair
		Cost		Value
	Due in 1 year or less	$	64	$	64
	Due in 1-5 years	36		36
	Total marketable securities	$	100	$	100

Intangible_Assets_Tables

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Intangible assets with definitive lives	'
	Intangible assets with definite lives are amortized. These assets are summarized as follows:
		As of September 30, 2014							As of December 31, 2013
	(millions)	Gross		Accumulated			Net		Gross		Accumulated			Net
		Carrying		Amortization					Carrying		Amortization
		Amount							Amount
	Intangible Assets with Definite Lives:
	Customer relationships	$	70	$	(53	)	$	17	$	70	$	(48	)	$	22
	Other	9		(7		)	2		9		(6		)	3
	Total	$	79	$	(60	)	$	19	$	79	$	(54	)	$	25
Estimated annual amortization expense intangible assets	'
	Estimated amortization expense for the remainder of 2014 and for future years is as follows:
	(millions)	2014		2015			2016		2017		2018			2019 and thereafter
	Estimated future amortization expense	$	1	$	7		$	7	$	2	$	1		$	1
Schedule of indefinite-lived intangible assets	'
	Intangible assets with indefinite lives are not amortized. These assets are summarized as follows:
		As of September 30, 2014							As of December 31, 2013
	(millions)	Gross		Accumulated Impairment Charges			Net		Gross		Accumulated Impairment Charges			Net
		Carrying							Carrying
		Amount							Amount
	Intangible Assets with Indefinite Lives:
	Trade names	$	22	$	—		$	22	$	22	$	—		$	22
	Other	8		1			7		8		1			7
	Total	$	30	$	1		$	29	$	30	$	1		$	29

Debt_Tables

Debt (Tables)	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Schedule of long-term debt instruments	'
	Total debt, including the current portion of long-term debt, consisted of the following:
	(millions)	September 30,		December 31,
		2014		2013
	5.875% senior notes due 2021	$	350	$	350
	6.3% senior notes due 2016	500		500
	7.75% senior notes due 2018, net of discount	500		500
	7.875% senior notes due 2020, net of discount	249		249
	8.375% senior notes due 2018	350		350
	9.75% senior notes due 2014, net of discount	—		59
	10% convertible senior notes due 2018, net of discount	—		72
	Ship mortgage facility (includes $4 million of current portion of long-term debt)	22		25
	Credit facilities of Oman joint ventures	—		11
	Industrial revenue bonds (due 2028 through 2034)	239		239
	Total	$	2,210	$	2,355

Derivative_Instruments_Tables

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Pretax effects of derivative instruments on consolidated statements of operations	'
	The following are the pretax effects of derivative instruments on the consolidated statements of operations for the three months ended September 30, 2014 and 2013.
		Amount of Gain or (Loss)								Location of Gain or (Loss)		Amount of Gain or (Loss) Reclassified from
		Recognized in								Reclassified from		AOCI into Income
		Other Comprehensive Income on Derivatives (Effective Portion)								AOCI into Income		(Effective Portion)
										(Effective Portion)
	(millions)	2014				2013						2014		2013
	Derivatives in Cash Flow Hedging Relationships
	Commodity contracts	$	(3	)		$	(1	)		Cost of products sold		$	—	$	—
	Foreign exchange contracts	3				(1		)		Cost of products sold		1		1
	Total	$	—			$	(2	)				$	1	$	1
			Location of Gain or (Loss)		Amount of Gain or (Loss) Recognized in Income
			Recognized in Income		on Derivatives
			on Derivatives
	(millions)				2014				2013
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts		Cost of products sold		$	(1	)		$	—
	Total				$	(1	)		$	—
	The following are the pretax effects of derivative instruments on the consolidated statements of operations for the nine months ended September 30, 2014 and 2013.
		Amount of Gain or (Loss)								Location of Gain or (Loss)		Amount of Gain or (Loss) Reclassified from
		Recognized in								Reclassified from		AOCI into Income
		Other Comprehensive Income on Derivatives (Effective Portion)								AOCI into Income		(Effective Portion)
										(Effective Portion)
	(millions)	2014				2013						2014		2013
	Derivatives in Cash Flow Hedging Relationships
	Commodity contracts	$	(1	)		$	(1	)		Cost of products sold		$	2	$	(1	)
	Foreign exchange contracts	3				2				Cost of products sold		2		2
	Total	$	2			$	1					$	4	$	1
			Location of Gain or (Loss)		Amount of Gain or (Loss) Recognized in Income
			Recognized in Income		on Derivatives
			on Derivatives
	(millions)				2014				2013
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts		Cost of products sold		$	—			$	1
	Total				$	—			$	1
Fair values of derivative instruments and the location on the consolidated balance sheets	'
	he following are the fair values of derivative instruments and the location on our consolidated balance sheets as of September 30, 2014 and December 31, 2013.
		Balance Sheet	Fair Value								Balance Sheet	Fair Value
		Location									Location
	(millions)		9/30/14				12/31/13					9/30/14		12/31/13
	Derivatives in Cash Flow Hedging Relationships
	Commodity contracts	Other current assets	$	2			$	2			Accrued expenses	$	4	$	—
	Commodity contracts	Other assets	—				—				Other liabilities	1		—
	Foreign exchange contracts	Other current assets	1				1				Accrued expenses	—		—
	Foreign exchange contracts	Other assets	1				—				Other liabilities	—		—
	Total derivatives in cash flow hedging relationships		$	4			$	3				$	5	$	—
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts	Other current assets	$	1			$	2			Accrued expenses	$	1	$	—
	Total derivatives not designated as hedging instruments		$	1			$	2				$	1	$	—
	Total derivatives	Total assets	$	5			$	5			Total liabilities	$	6	$	—

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Assets and liabilities measured at fair value on a recurring basis	'
	Our assets and liabilities measured at fair value on a recurring basis were as follows:
		Quoted Prices				Significant					Significant				Total
		in Active				Other					Unobservable
		Markets for				Observable					Inputs
		Identical				Inputs					(Level 3)
		Assets				(Level 2)
		(Level 1)
	(millions)	9/30/14		12/31/13		9/30/14			12/31/13		9/30/14		12/31/13		9/30/14			12/31/13
	Cash equivalents	$	133	$	549	$	13		$	24	$	—	$	—	$	146		$	573
	Marketable securities:
	Corporate debt securities	—		—		60			87		—		—		60			87
	U.S. government and agency debt securities	—		—		6			12		—		—		6			12
	Asset-backed debt securities	—		—		13			20		—		—		13			20
	Certificates of deposit	—		—		15			17		—		—		15			17
	Municipal debt securities	—		—		6			6		—		—		6			6
	Derivative assets	—		—		5			5		—		—		5			5
	Derivative liabilities	—		—		(6		)	—		—		—		(6		)	—

Employee_Retirement_Plans_Tabl

Employee Retirement Plans (Tables)	9 Months Ended
	Sep. 30, 2014
Compensation and Retirement Disclosure [Abstract]	'
Components of net pension and postretirement benefits costs	'
	The components of net pension and postretirement benefits costs are summarized in the following table:
		Three months ended September 30,						Nine months ended September 30,
	(millions)	2014			2013			2014			2013
	Pension:
	Service cost of benefits earned	$	9		$	10		$	27		$	29
	Interest cost on projected benefit obligation	16			16			49			47
	Expected return on plan assets	(20		)	(19		)	(60		)	(57		)
	Net amortization	7			11			19			34
	Net pension cost	$	12		$	18		$	35		$	53
	Postretirement:
	Service cost of benefits earned	$	1		$	1		$	2		$	3
	Interest cost on projected benefit obligation	1			2			5			5
	Net amortization	(8		)	(9		)	(26		)	(26		)
	Net postretirement benefit	$	(6	)	$	(6	)	$	(19	)	$	(18	)

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Awards granted during the period and assumptions used to determine fair value	'
	Awards granted during the first nine months of 2014 and assumptions used to determine fair value were as follows:
		MSUs			Performance Shares			RSUs
	Awards granted	364,180			111,287			57,500
	Weighted average fair value	$	40.2		$	46.46		$	33.37
	Expected volatility	54.93		%	54.93		%	N/A
	Risk-free rate (a)	0.63		%	0.63		%	N/A
	Expected term (in years) (b)	2.94			2.94			N/A
	Expected dividends	—			—			N/A
	(a)	The risk-free rate was based on zero coupon U.S. government issues at the time of grant.
	(b)	The expected term represents the period from the valuation date to the end of the performance period.

Supplemental_Balance_Sheet_Inf1

Supplemental Balance Sheet Information (Tables)	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Schedule of inventories	'
	Total inventories consisted of the following:
	(millions)	30-Sep-14			31-Dec-13
	Finished goods and work in progress	$	264		$	270
	Raw materials	62			62
	Total	$	326		$	332
Changes in the liability for asset retirement obligations	'
	Changes in the liability for asset retirement obligations consisted of the following:
		Nine months ended September 30,
	(millions)	2014			2013
	Balance as of January 1	$	132		$	139
	Accretion expense	6			5
	Liabilities incurred	1			2
	Changes in estimated cash flows (a)	(13		)	(11		)
	Liabilities settled	(2		)	(1		)
	Foreign currency translation	(2		)	(2		)
	Balance as of September 30	$	122		$	132
	(a)	Changes in estimated cash flows for the nine months ended September 30, 2014 includes changes in estimates primarily related to reclamation activities for our gypsum quarry and ship loading facility in Windsor, Nova Scotia, Canada, which we permanently closed during the third quarter of 2011, and our mining operation in Little Narrows, Nova Scotia, Canada.

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Changes in the balances of each component of AOCI	'
	Changes in the balances of each component of AOCI for the nine months ended September 30, 2014 and 2013 were as follows:
		Derivatives							Defined Benefit Plans								Foreign						AOCI
																	Currency Translation
	(millions)	2014			2013				2014				2013				2014			2013			2014			2013
	Balance as of January 1	$	35		$	32			$	(32	)		$	(303	)		$	21		$	38		$	24		$	(233	)
	Other comprehensive income (loss) before reclassifications, net of tax	1			—				(6		)		(15		)		(28		)	(12		)	(33		)	(27		)
	Less: Amounts reclassified from AOCI, net of tax	4			—				9				(8		)		5			—			18			(8		)
	Net other comprehensive income (loss)	(3		)	—				(15		)		(7		)		(33		)	(12		)	(51		)	(19		)
	Balance as of September 30	$	32		$	32			$	(47	)		$	(310	)		$	(12	)	$	26		$	(27	)	$	(252	)
Amounts reclassified from AOCI, net of tax	'
	Amounts reclassified from AOCI, net of tax, for the three months and nine months ended September 30, 2014 and 2013, were as follows:
			Three months ended September 30,							Nine months ended September 30,
			2014			2013				2014				2013
	Derivatives
	Net reclassification from AOCI for cash flow hedges included in cost of products sold		$	1		$	1			$	4			$	1
	Income tax expense on reclassification from AOCI included in income tax expense (benefit)		—			(1		)		—				(1		)
	Net amount reclassified from AOCI		$	1		$	—			$	4			$	—
	Defined Benefit Plans
	Net reclassification from AOCI for amortization of prior service cost included in cost of products sold		$	2		$	(2	)		$	5			$	(7	)
	Net reclassification from AOCI for amortization of prior service cost included in selling and administrative expenses		1			(1		)		3				(2		)
	Income tax expense on reclassification from AOCI included in income tax expense (benefit)		—			—				(1		)		1
	Net amount reclassified from AOCI		$	3		$	(3	)		$	9			$	(8	)
	Foreign Currency Translation
	Net reclassification from AOCI for translation gains realized upon the deconsolidation of foreign subsidiaries included in selling and administrative expenses		$	—		$	—			$	5			$	—
	Income tax expense on reclassification from AOCI included in income tax expense (benefit)		—			—				—				—
	Net amount reclassified from AOCI		$	—		$	—			$	5			$	—

Organization_Consolidation_and1

Organization, Consolidation and Presentation of Financial Statements (Details)	Sep. 30, 2014	Feb. 27, 2014
USG Boral Building Products	'	'
Schedule of Equity Method Investments [Line Items]	'	'
Ownership Percentage - Other equity method investment	50.00%	50.00%
Boral Limited	'	'
Schedule of Equity Method Investments [Line Items]	'	'
Ownership percentage by joint venture partner of equity method investment	'	50.00%

Equity_Method_Investments_Deta

Equity Method Investments (Details) (USD $)

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Feb. 27, 2014

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

In Millions, unless otherwise specified

USG Boral Building Products

USG Boral Building Products

USG Boral Building Products

Other equity method investments

Other equity method investments

Other equity method investments

Other equity method investments

Other equity method investments

Other equity method investments

Minimum

Minimum

Maximum

Maximum

Schedule of Equity Method Investments [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Equity method investments

$739

$73

$692

[1]

$692

[1]

$676

$47

$73

'

'

'

'

Ownership Percentage

'

'

50.00%

50.00%

50.00%

'

'

33.00%

33.00%

50.00%

50.00%

Transaction costs included in equity method investment carrying value

'

'

$32

$32

'

'

'

'

'

'

'

[1]

The carrying value of our investment in UBBP as of September 30, 2014, includes transaction costs of approximately $32 million incurred in the fourth quarter of 2013 and first nine months of 2014.

Equity_Method_Investments_Deta1

Equity Method Investments (Details 1) (USD $)	3 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Schedule of Equity Method Investments [Line Items]	'		'		'		'
USG share of income from investment accounted for using the equity method	$12		$1		$20		$2
USG Boral Building Products	'		'		'		'
Schedule of Equity Method Investments [Line Items]	'		'		'		'
Net sales	286		'		655	[1]	'
Gross profit	77		'		179	[1]	'
Operating profit	31		'		57	[1]	'
Net income	25		'		42	[1]	'
Net income attributable to USG Boral Building Products	24		'		39	[1]	'
USG share of income from investment accounted for using the equity method	12		'		19	[1]	'
Other equity method investments	'		'		'		'
Schedule of Equity Method Investments [Line Items]	'		'		'		'
USG share of income from investment accounted for using the equity method	$0	[2]	$1	[2]	$1	[2]	$2	[2]
[1]	Operating results are presented for UBBP for the seven months ended September 30, 2014.
[2]	Amounts represent our share of income or loss from all equity method investments, other than UBBP. For the nine months ended September 30, 2014, the amount reflected includes two months of our share of equity method earnings from the joint ventures which we had accounted for as equity method investments prior to being contributed to UBBP on February 27, 2014.

Equity_Method_Investments_Deta2

Equity Method Investments (Details Textual) (USD $)

0 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

1 Months Ended

In Millions, unless otherwise specified

Feb. 27, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Feb. 27, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Feb. 27, 2014

Sep. 30, 2014

Dec. 31, 2013

Oct. 31, 2013

Feb. 27, 2014

Feb. 27, 2014

Oct. 31, 2014

USG Boral Building Products

USG Boral Building Products

USG Boral Building Products

Other equity method investments

Other equity method investments

Other equity method investments

Other equity method investments

Other equity method investments

Boral Limited

5.875% senior notes due 2021

5.875% senior notes due 2021

5.875% senior notes due 2021

Base purchase price

Adjustments to purchase price

Subsequent event

Post closing adjustments to purchase price

Schedule of Equity Method Investments [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ownership Percentage - Other equity method investment

'

'

'

'

'

'

50.00%

50.00%

50.00%

'

'

'

'

'

'

'

'

'

'

'

'

Ownership percentage by joint venture partner of equity method investment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

50.00%

'

'

'

'

'

'

Payments to acquire equity method investments

$513

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$500

$13

$2

Long-term debt

'

2,210

'

2,210

'

2,355

'

'

'

'

'

'

'

'

'

350

350

350

'

'

'

Debt instrument interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5.88%

5.88%

5.88%

'

'

'

Range of outcomes in contingent consideration arrangements, value, high

'

'

'

'

'

'

75

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Contingent consideration for first performance period

'

'

'

'

'

'

25

'

'

'

'

'

'

'

'

'

'

'

'

'

'

First performance period for contingent consideration

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Contingent consideration for second performance period

'

'

'

'

'

'

50

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Second performance period for contingent consideration

'

'

'

'

'

'

'5 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Equity method investments

'

739

'

739

'

73

676

692

[1]

692

[1]

47

'

47

'

73

'

'

'

'

'

'

'

Gain on deconsolidation of subsidiaries and consolidated joint ventures

'

0

0

27

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gain (loss) on revaluation of retained investment on deconsolidation

'

'

'

11

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted average discount rate

'

'

'

11.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted average long-term growth rate

'

'

'

2.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Present value of contingent liability for contingent consideration for equity method investment

'

23

'

23

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Changes in AOCI - foreign currency translation

'

-39

5

-28

-12

'

'

'

-13

'

'

'

'

'

'

'

'

'

'

'

'

USG share of income from investment accounted for using the equity method

'

$12

$1

$20

$2

'

'

$12

$19

[2]

$0

[3]

$1

[3]

$1

[3]

$2

[3]

'

'

'

'

'

'

'

'

[1]

The carrying value of our investment in UBBP as of September 30, 2014, includes transaction costs of approximately $32 million incurred in the fourth quarter of 2013 and first nine months of 2014.

[2]

Operating results are presented for UBBP for the seven months ended September 30, 2014.

[3]

Amounts represent our share of income or loss from all equity method investments, other than UBBP. For the nine months ended September 30, 2014, the amount reflected includes two months of our share of equity method earnings from the joint ventures which we had accounted for as equity method investments prior to being contributed to UBBP on February 27, 2014.

LongLived_Asset_Impairment_Cha1

Long-Lived Asset Impairment Charges (Details Textual) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Impaired Long-Lived Assets Held and Used [Line Items]	'	'	'	'
Long-lived asset impairment charges	$30	$0	$30	$0
Machinery, Equipment and Buildings | Empire, Nevada and New Orleans, Louisiana	'	'	'	'
Impaired Long-Lived Assets Held and Used [Line Items]	'	'	'	'
Long-lived asset impairment charges	16	'	'	'
Machinery, Equipment and Buildings | Gypsum, Ohio	'	'	'	'
Impaired Long-Lived Assets Held and Used [Line Items]	'	'	'	'
Long-lived asset impairment charges	2	'	'	'
Facilities	'	'	'	'
Impaired Long-Lived Assets Held and Used [Line Items]	'	'	'	'
Long-lived asset impairment charges	$12	'	'	'

Segments_Details

Segments (Details) (USD $)	3 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Net Sales:	'		'		'		'
Net sales	$972	[1]	$925	[2]	$2,770	[1],[2]	$2,655	[2]
Operating Profit (Loss):	'		'		'		'
Operating profit (loss)	22	[1]	75	[2]	186	[1],[2]	198	[2]
Long-lived asset impairment charges	30		0		30		0
Litigation settlement charge	-48		0		-48		0
Operating segments | Gypsum	'		'		'		'
Net Sales:	'		'		'		'
Net sales	621	[1]	580	[2]	1,778	[1],[2]	1,670	[2]
Operating Profit (Loss):	'		'		'		'
Operating profit (loss)	12	[1]	75	[2]	172	[1],[2]	188	[2]
Operating segments | Ceilings	'		'		'		'
Net Sales:	'		'		'		'
Net sales	137	[1],[3]	146	[2],[3]	392	[1],[2],[3]	428	[2],[3]
Operating Profit (Loss):	'		'		'		'
Operating profit (loss)	30	[1],[3]	23	[2],[3]	69	[1],[2],[3]	77	[2],[3]
Operating segments | Distribution	'		'		'		'
Net Sales:	'		'		'		'
Net sales	359	[1]	331	[2]	1,003	[1],[2]	931	[2]
Operating Profit (Loss):	'		'		'		'
Operating profit (loss)	4	[1]	3	[2]	9	[1],[2]	2	[2]
Operating segments | Corporate	'		'		'		'
Operating Profit (Loss):	'		'		'		'
Operating profit (loss)	-23	[1]	-25	[2]	-65	[1],[2]	-63	[2]
Eliminations	'		'		'		'
Net Sales:	'		'		'		'
Net sales	-145	[1]	-132	[2]	-403	[1],[2]	-374	[2]
Operating Profit (Loss):	'		'		'		'
Operating profit (loss)	($1)	[1]	($1)	[2]	$1	[1],[2]	($6)	[2]
[1]	Gypsum's operating profit for both the three and nine months ended September 30, 2014 included a litigation settlement charge of $48 million and long-lived asset impairment charges of $30 million
[2]	Net sales and operating profit (loss) have been recast for periods prior to April 1, 2014 to conform with the new presentation of reportable segments.
[3]	Ceilings' net sales and operating profit for the nine months ended September 30, 2014 includes the results, through February 27, 2014, of our wholly-owned subsidiaries and consolidated joint ventures that were contributed to UBBP.

Segment_Details_Textual

Segment (Details Textual) (USD $)	0 Months Ended
In Millions, unless otherwise specified	Feb. 27, 2014
Segment Reporting Information [Line Items]	'
Payments to acquire equity method investments	$513
USG Boral Building Products	'
Segment Reporting Information [Line Items]	'
Total assets contributed, net of cash	$139

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Income from continuing operations	($11)	$24	$92	$51
Less: Net income attributable to noncontrolling interest	1	0	1	0
Income (loss) from continuing operations attributable to USG	-12	24	91	51
Loss from discontinued operations, net of tax	0	-1	-1	-1
Net income (loss) attributable to USG	-12	23	90	50
Effect of dilutive securities - RSUs, MSUs, performance shares and stock options	0	0	0	0
Effect of dilutive securities - 10% convertible senior notes	0	0	2	0
Effect of dilutive securities - Deferred compensation program for non-employee directors	0	0	0	0
Income (loss) available to shareholders	($12)	$23	$92	$50
Average common shares	144,646,284	108,608,086	140,944,207	108,486,583
Dilutive RSUs, MSUs, performance shares and stock options	0	2,400,000	2,500,000	2,600,000
Common shares issuable upon conversion of our 10% convertible senior notes	0	0	3,500,000	0
Deferred shares associated with a deferred compensation program for non-employee directors	0	0	200,000	0
Average diluted common shares	144,646,284	111,008,421	147,087,399	111,052,333
Income (loss) from continuing operations per average common share	($0.09)	$0.23	$0.65	$0.48
Loss from discontinued operations per average common share	$0	($0.01)	($0.01)	($0.01)
Earnings (loss) per average common share	($0.09)	$0.22	$0.64	$0.47
Income (loss) from continuing operations per average dilutive share	($0.09)	$0.22	$0.63	$0.47
Loss from discontinued operations	$0	($0.01)	($0.01)	($0.01)
Earnings (loss) per average diluted common share	($0.09)	$0.21	$0.62	$0.46

Earnings_Per_Share_Details_1

Earnings Per Share (Details 1)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
MSUs, performance shares, RSUs and stock options	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
MSUs, performance shares, RSUs and stock options	5.6	2	2.7	2.2
Ten Percent Convertible Senior Notes due Two Thousand Eighteen [Member] | 10% convertible senior notes due 2018	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
10% convertible senior notes due 2018	0	35.1	0	35.1

Earnings_Per_Share_Details_Tex

Earnings Per Share (Details Textual) (10% convertible senior notes due 2018, net of discount, USD $)	1 Months Ended
In Millions, except Share data, unless otherwise specified	Apr. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2014
10% convertible senior notes due 2018, net of discount	'	'	'	'
Earnings (Loss) Per Share [Line Items]	'	'	'	'
Debt conversion, original amount of debt	$75	$75	$325	'
Interest rate on debt converted	'	'	10.00%	10.00%
Debt conversion, shares issued for converted instrument	6,578,946	'	28,500,000	'

Marketable_Securities_Details

Marketable Securities (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Investments in marketable securities	'	'
Amortized Cost	$100	$142
Fair Value	100	142
Corporate debt securities	'	'
Investments in marketable securities	'	'
Amortized Cost	60	87
Fair Value	60	87
U.S. government and agency debt securities	'	'
Investments in marketable securities	'	'
Amortized Cost	6	12
Fair Value	6	12
Asset-backed debt securities	'	'
Investments in marketable securities	'	'
Amortized Cost	13	20
Fair Value	13	20
Certificates of deposit	'	'
Investments in marketable securities	'	'
Amortized Cost	15	17
Fair Value	15	17
Municipal debt securities	'	'
Investments in marketable securities	'	'
Amortized Cost	6	6
Fair Value	$6	$6

Marketable_Securities_Details_

Marketable Securities (Details 1) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Contractual maturities of marketable securities	'	'
Due in 1 year or less, amortized cost	$64	'
Due in 1-5 years, amortized cost	36	'
Marketable securities, amortized cost	100	142
Due in 1 year or less, fair value	64	'
Due in 1-5 years, fair value	36	'
Marketable securities, fair value	$100	$142

Marketable_Securities_Details_1

Marketable Securities (Details Textual) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Investments, Debt and Equity Securities [Abstract]	'
Sales and maturities of marketable securities	$166

Intangible_Assets_Details

Intangible Assets (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Intangible assets with definite lives	'	'
Gross Carrying Amount	$79	$79
Accumulated Amortization	-60	-54
Net	19	25
Customer relationships	'	'
Intangible assets with definite lives	'	'
Gross Carrying Amount	70	70
Accumulated Amortization	-53	-48
Net	17	22
Other	'	'
Intangible assets with definite lives	'	'
Gross Carrying Amount	9	9
Accumulated Amortization	-7	-6
Net	$2	$3

Intangible_Assets_Details_1

Intangible Assets (Details 1) (USD $)	Sep. 30, 2014
In Millions, unless otherwise specified
Estimated annual amortization expense intangible assets	'
Estimated future amortization expense, 2014	$1
Estimated future amortization expense, 2015	7
Estimated future amortization expense, 2016	7
Estimated future amortization expense, 2017	2
Estimated future amortization expense, 2018	1
Estimated future amortization expense, 2019 and thereafter	$1

Intangible_Assets_Details_2

Intangible Assets (Details 2) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Intangible assets with indefinite lives	'	'
Gross Carrying Amount	$30	$30
Accumulated Impairment Charges	1	1
Net	29	29
Trade names	'	'
Intangible assets with indefinite lives	'	'
Gross Carrying Amount	22	22
Accumulated Impairment Charges	0	0
Net	22	22
Other	'	'
Intangible assets with indefinite lives	'	'
Gross Carrying Amount	8	8
Accumulated Impairment Charges	1	1
Net	$7	$7

Intangible_Assets_Details_Text

Intangible Assets (Details Textual) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'	'	'	'	'
Amortization expense of intangible assets	$2,000,000	$2,000,000	$6,000,000	$6,000,000	'
Indefinite-lived assets held for sale	$5,000,000	'	$5,000,000	'	$0

Debt_Details

Debt (Details) (USD $)

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Oct. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Aug. 01, 2014

Dec. 31, 2013

Sep. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

In Millions, unless otherwise specified

5.875% senior notes due 2021

5.875% senior notes due 2021

5.875% senior notes due 2021

6.3% senior notes due 2016

6.3% senior notes due 2016

7.75% senior notes due 2018, net of discount

7.75% senior notes due 2018, net of discount

7.875% senior notes due 2020, net of discount

7.875% senior notes due 2020, net of discount

8.375% senior notes due 2018

8.375% senior notes due 2018

9.75% senior notes due 2014, net of discount

9.75% senior notes due 2014, net of discount

9.75% senior notes due 2014, net of discount

10% convertible senior notes due 2018, net of discount

10% convertible senior notes due 2018, net of discount

10% convertible senior notes due 2018, net of discount

Ship mortgage facility

Ship mortgage facility

Credit facilities of Oman joint ventures

Credit facilities of Oman joint ventures

Industrial revenue bonds (due 2028 through 2034)

Industrial revenue bonds (due 2028 through 2034)

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total debt

$2,210

$2,355

$350

$350

$350

$500

$500

$500

$500

$249

$249

$350

$350

$0

$59

$59

$0

$72

$72

$22

$25

$0

$11

$239

$239

Interest rate of convertible senior notes

'

'

-5.88%

-5.88%

-5.88%

-6.30%

-6.30%

-7.75%

-7.75%

-7.88%

-7.88%

-8.38%

-8.38%

-9.75%

'

-9.75%

-10.00%

'

-10.00%

'

'

'

'

'

'

Current portion of long-term debt

$4

$63

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$4

$4

'

'

'

'

Debt_Details_Textual

Debt (Details Textual) (USD $)

Sep. 30, 2014

Apr. 17, 2014

Dec. 31, 2013

Sep. 30, 2014

Oct. 22, 2014

Oct. 22, 2014

Oct. 22, 2014

Oct. 22, 2014

Sep. 30, 2014

Feb. 28, 2014

Dec. 31, 2013

Apr. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Aug. 01, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Credit facility

Credit facility

Credit facility

Credit facility

Letter of credit

Credit facilities of Oman joint ventures

Credit facilities of Oman joint ventures

10% convertible senior notes due 2018, net of discount

10% convertible senior notes due 2018, net of discount

10% convertible senior notes due 2018, net of discount

10% convertible senior notes due 2018, net of discount

9.75% senior notes due 2014, net of discount

9.75% senior notes due 2014, net of discount

9.75% senior notes due 2014, net of discount

6.3% senior notes due 2016

6.3% senior notes due 2016

7.75% senior notes due 2018, net of discount

7.75% senior notes due 2018, net of discount

8.375% senior notes due 2018

8.375% senior notes due 2018

Subsequent event

Subsequent event

CGC, Inc.

Subsequent event

Subsequent event

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term debt

$2,210,000,000

'

$2,355,000,000

'

'

'

'

'

'

'

$11,000,000

'

$72,000,000

$72,000,000

$0

$0

$59,000,000

$59,000,000

$500,000,000

$500,000,000

$500,000,000

$500,000,000

$350,000,000

$350,000,000

Gross long term debt

'

'

'

'

'

'

'

'

'

'

'

'

75,000,000

'

'

'

'

'

'

'

'

'

'

'

Interest rate on debt converted

'

'

'

'

'

'

'

'

'

'

'

'

'

10.00%

10.00%

9.75%

'

9.75%

6.30%

6.30%

7.75%

7.75%

8.38%

8.38%

Unamortized discount

'

'

'

'

'

'

'

'

'

'

'

'

3,000,000

'

'

'

'

'

'

'

'

'

'

'

Debt conversion, original amount of debt

'

'

'

'

'

'

'

'

'

'

'

75,000,000

75,000,000

325,000,000

'

'

'

'

'

'

'

'

'

'

Debt conversion, shares issued for converted instrument

'

'

'

'

'

'

'

'

'

'

'

6,578,946

'

28,500,000

'

'

'

'

'

'

'

'

'

'

Required minimum fixed charge coverage ratio per credit agreement covenant

'

'

'

1.1

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate principal amount

'

'

'

40,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of credit facility rate applied aggregate revolving commitments activating fixed charge coverage ratio covenants

'

'

'

15.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Actual fixed charge coverage ratio

'

'

'

1.14

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount of letters of credit outstanding

'

'

'

54,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Borrowing available under credit facility

'

'

'

311,000,000

'

'

'

200,000,000

35,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Outstanding lines of credit

'

'

'

0

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount of minimum liquidity condition

'

500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of credit facility increase in borrowing

'

'

'

'

'

'

'

'

'

3,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair value of debt

2,362,000,000

'

2,659,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of credit facility maximum limit

'

'

'

$400,000,000

'

$450,000,000

$50,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fixed Charge Coverage Ratio, Percentage of Committed Borrowings, Threshold Requiring Compliance

'

'

'

'

10.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative_Instruments_Details

Derivative Instruments (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivatives in Cash Flow Hedging Relationships | Cash Flow Hedging	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain or (Loss) Recognized in Other Comprehensive Income on Derivatives (Effective Portion)	$0	($2)	$2	$1
Amount of Gain or (Loss) Reclassified from AOCI into Income (Effective Portion)	1	1	4	1
Derivatives in Cash Flow Hedging Relationships | Commodity contracts | Cash Flow Hedging	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain or (Loss) Recognized in Other Comprehensive Income on Derivatives (Effective Portion)	-3	-1	-1	-1
Derivatives in Cash Flow Hedging Relationships | Commodity contracts | Cost of products sold | Cash Flow Hedging	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain or (Loss) Reclassified from AOCI into Income (Effective Portion)	0	0	2	-1
Derivatives in Cash Flow Hedging Relationships | Foreign exchange contracts | Cash Flow Hedging	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain or (Loss) Recognized in Other Comprehensive Income on Derivatives (Effective Portion)	3	-1	3	2
Derivatives in Cash Flow Hedging Relationships | Foreign exchange contracts | Cost of products sold | Cash Flow Hedging	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain or (Loss) Reclassified from AOCI into Income (Effective Portion)	1	1	2	2
Derivatives Not Designated as Hedging Instruments | Cost of products sold	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain or (Loss) Recognized in Income on Derivatives	-1	0	0	1
Derivatives Not Designated as Hedging Instruments | Commodity contracts | Cost of products sold	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain or (Loss) Recognized in Income on Derivatives	($1)	$0	$0	$1

Derivative_Instruments_Details1

Derivative Instruments (Details 1) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Derivative assets	$5	$5
Derivative liabilities	6	0
Derivatives in Cash Flow Hedging Relationships	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets	4	3
Derivative liabilities	5	0
Derivatives Not Designated as Hedging Instruments	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets	1	2
Derivative liabilities	1	0
Derivatives Not Designated as Hedging Instruments | Commodity contracts | Other current assets	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets	1	2
Derivatives Not Designated as Hedging Instruments | Commodity contracts | Accrued expenses	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative liabilities	1	0
Cash Flow Hedging | Derivatives in Cash Flow Hedging Relationships | Commodity contracts | Other current assets	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets	2	2
Cash Flow Hedging | Derivatives in Cash Flow Hedging Relationships | Commodity contracts | Other assets	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets	0	0
Cash Flow Hedging | Derivatives in Cash Flow Hedging Relationships | Commodity contracts | Accrued expenses	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative liabilities	4	0
Cash Flow Hedging | Derivatives in Cash Flow Hedging Relationships | Commodity contracts | Other liabilities	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative liabilities	1	0
Cash Flow Hedging | Derivatives in Cash Flow Hedging Relationships | Foreign exchange contracts | Other current assets	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets	1	1
Cash Flow Hedging | Derivatives in Cash Flow Hedging Relationships | Foreign exchange contracts | Other assets	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets	1	0
Cash Flow Hedging | Derivatives in Cash Flow Hedging Relationships | Foreign exchange contracts | Accrued expenses	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative liabilities	0	0
Cash Flow Hedging | Derivatives in Cash Flow Hedging Relationships | Foreign exchange contracts | Other liabilities	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative liabilities	$0	$0

Derivative_Instruments_Details2

Derivative Instruments (Details Textual) (USD $)	9 Months Ended
	Sep. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]	'
Typical hedging period	'2 years
Net liability aggregate fair value	$1,000,000
Collateral provided to counterparties related to derivatives	6,000,000
Commodity contracts	'
Derivative Instruments, Gain (Loss) [Line Items]	'
Nonmonetary notional amount of derivatives	22,000,000
Loss on cash flow hedge ineffectiveness	0
Foreign exchange contracts	'
Derivative Instruments, Gain (Loss) [Line Items]	'
Loss on cash flow hedge ineffectiveness	0
Notional amounts of foreign exchange forward contracts	69,000,000
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges | Commodity contracts	'
Derivative Instruments, Gain (Loss) [Line Items]	'
Unrealized loss that remained in AOCI from cash flow hedges, net of tax	-3,000,000
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges | Foreign exchange contracts	'
Derivative Instruments, Gain (Loss) [Line Items]	'
Unrealized loss that remained in AOCI from cash flow hedges, net of tax	$2,000,000

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets and liabilities measured at fair value on a recurring basis	'	'
Cash equivalents	$146	$573
Fair Value	100	142
Derivative assets	5	5
Derivative liabilities	-6	0
Corporate debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	60	87
U.S. government and agency debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	6	12
Asset-backed debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	13	20
Certificates of deposit	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	15	17
Municipal debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	6	6
Quoted Prices in Active Markets for Identical Assets (Level 1)	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Cash equivalents	133	549
Derivative assets	0	0
Derivative liabilities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. government and agency debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Asset-backed debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Certificates of deposit	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Municipal debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	0	0
Significant Other Observable Inputs (Level 2)	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Cash equivalents	13	24
Derivative assets	5	5
Derivative liabilities	-6	0
Significant Other Observable Inputs (Level 2) | Corporate debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	60	87
Significant Other Observable Inputs (Level 2) | U.S. government and agency debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	6	12
Significant Other Observable Inputs (Level 2) | Asset-backed debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	13	20
Significant Other Observable Inputs (Level 2) | Certificates of deposit	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	15	17
Significant Other Observable Inputs (Level 2) | Municipal debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	6	6
Significant Unobservable Inputs (Level 3)	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Cash equivalents	0	0
Derivative assets	0	0
Derivative liabilities	0	0
Significant Unobservable Inputs (Level 3) | Corporate debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	0	0
Significant Unobservable Inputs (Level 3) | U.S. government and agency debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	0	0
Significant Unobservable Inputs (Level 3) | Asset-backed debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	0	0
Significant Unobservable Inputs (Level 3) | Certificates of deposit	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	0	0
Significant Unobservable Inputs (Level 3) | Municipal debt securities	'	'
Assets and liabilities measured at fair value on a recurring basis	'	'
Fair Value	$0	$0

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details Textual) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'	'	'	'
Long-lived asset impairment charges	$30	$0	$30	$0

Employee_Retirement_Plans_Deta

Employee Retirement Plans (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Pension	'	'	'	'
Components of net pension and postretirement benefits costs	'	'	'	'
Service cost of benefits earned	$9	$10	$27	$29
Interest cost on projected benefit obligation	16	16	49	47
Expected return on plan assets	-20	-19	-60	-57
Net amortization	7	11	19	34
Net pension cost	12	18	35	53
Postretirement	'	'	'	'
Components of net pension and postretirement benefits costs	'	'	'	'
Service cost of benefits earned	1	1	2	3
Interest cost on projected benefit obligation	1	2	5	5
Net amortization	-8	-9	-26	-26
Net pension cost	($6)	($6)	($19)	($18)

Employee_Retirement_Plans_Deta1

Employee Retirement Plans (Details Textual) (USD $)	9 Months Ended				3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2014
	United States pension plan	Canada pension plan	Other domestic and foreign pension plans	Pension	Scenario, Forecast [Member]	Scenario, Forecast [Member]
					Minimum	Maximum
					Other domestic and foreign pension plans	Other domestic and foreign pension plans
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'	'	'
Contribution by employer	$50	$8	$2	'	'	'
Estimated employer contributions in current fiscal year	'	'	'	61	'	'
Defined Benefit Plan, Settlement Charge	'	'	'	'	$12	$14

ShareBased_Compensation_Detail

Share-Based Compensation (Details) (USD $)	9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014
MSUs	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Awards granted	364,180
Weighted average fair value	$40.20
Expected volatility	54.93%
Risk-free rate	0.63%	[1]
Expected term (in years)	'2 years 11 months 10 days	[2]
Expected dividends	$0
Performance Shares	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Awards granted	111,287
Weighted average fair value	$46.46
Expected volatility	54.93%
Risk-free rate	0.63%	[1]
Expected term (in years)	'2 years 11 months 10 days	[2]
Expected dividends	$0
RSUs	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Awards granted	57,500
Weighted average fair value	$33.37
[1]	The risk-free rate was based on zero coupon U.S. government issues at the time of grant.
[2]	The expected term represents the period from the valuation date to the end of the performance period.

ShareBased_Compensation_Detail1

Share-Based Compensation (Details Textual)	9 Months Ended
	Sep. 30, 2014
MSUs	'
Share Based Compensation [Abstract]	'
Vesting period	'3 years
Performance Shares	'
Share Based Compensation [Abstract]	'
Vesting period	'3 years
Minimum | MSUs	'
Share Based Compensation [Abstract]	'
Minimum of range for number of shares earned	0.00%
Minimum | Performance Shares	'
Share Based Compensation [Abstract]	'
Minimum of range for number of shares earned	0.00%
Maximum | MSUs	'
Share Based Compensation [Abstract]	'
Maximum of range for number of shares earned	150.00%
Maximum | Performance Shares	'
Share Based Compensation [Abstract]	'
Maximum of range for number of shares earned	200.00%

Supplemental_Balance_Sheet_Inf2

Supplemental Balance Sheet Information (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Inventories	'	'
Finished goods and work in progress	$264	$270
Raw materials	62	62
Total	$326	$332

Supplemental_Balance_Sheet_Inf3

Supplemental Balance Sheet Information (Details 1) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]	'		'
Beginning balance	$132		$139
Accretion expense	6		5
Liabilities incurred	1		2
Changes in estimated cash flows	-13	[1]	-11	[1]
Liabilities settled	-2		-1
Foreign currency translation	-2		-2
Ending balance	$122		$132
[1]	Changes in estimated cash flows for the nine months ended September 30, 2014 includes changes in estimates primarily related to reclamation activities for our gypsum quarry and ship loading facility in Windsor, Nova Scotia, Canada, which we permanently closed during the third quarter of 2011, and our mining operation in Little Narrows, Nova Scotia, Canada.

Supplemental_Balance_Sheet_Inf4

Supplemental Balance Sheet Information (Details Textual) (USD $)	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Supplemental Balance Sheet Information [Abstract]	'	'	'
Interest accrued on debt	$48,000,000	'	$48,000,000
Gain on sale of surplus property	'	12,000,000	'
Indefinite-lived assets held for sale	$5,000,000	'	$0

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Beginning balance	'	'	$24	($233)
Other comprehensive income (loss) before reclassifications, net of tax	'	'	-33	-27
Less: Amounts reclassified from AOCI, net of tax	'	'	18	-8
Other comprehensive income (loss), net of tax	-41	3	-51	-19
Ending balance	-27	-252	-27	-252
Derivatives	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Beginning balance	'	'	35	32
Other comprehensive income (loss) before reclassifications, net of tax	'	'	1	0
Less: Amounts reclassified from AOCI, net of tax	'	'	4	0
Other comprehensive income (loss), net of tax	'	'	-3	0
Ending balance	32	32	32	32
Defined Benefit Plans	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Beginning balance	'	'	-32	-303
Other comprehensive income (loss) before reclassifications, net of tax	'	'	-6	-15
Less: Amounts reclassified from AOCI, net of tax	'	'	9	-8
Other comprehensive income (loss), net of tax	'	'	-15	-7
Ending balance	-47	-310	-47	-310
Foreign Currency Translation	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Beginning balance	'	'	21	38
Other comprehensive income (loss) before reclassifications, net of tax	'	'	-28	-12
Less: Amounts reclassified from AOCI, net of tax	'	'	5	0
Other comprehensive income (loss), net of tax	'	'	-33	-12
Ending balance	($12)	$26	($12)	$26

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income (Loss) (Details 1) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Net reclassification from AOCI for cash flow hedges included in cost of products sold	$796	$770	$2,276	$2,225
Net reclassification from AOCI for amortization of prior service cost included in selling and administrative expenses	76	80	230	229
Income tax expense on reclassification from AOCI included in income tax expense (benefit)	-2	-2	-7	-1
Net income	-11	23	91	50
Estimated after-tax loss on derivatives to be reclassified from AOCI to earnings within the next 12 months	'	'	1	'
Derivatives | Amounts reclassified from AOCI, net of tax	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Net reclassification from AOCI for cash flow hedges included in cost of products sold	1	1	4	1
Income tax expense on reclassification from AOCI included in income tax expense (benefit)	0	-1	0	-1
Net income	1	0	4	0
Defined Benefit Plans | Amounts reclassified from AOCI, net of tax	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Net reclassification from AOCI for cash flow hedges included in cost of products sold	2	-2	5	-7
Net reclassification from AOCI for amortization of prior service cost included in selling and administrative expenses	1	-1	3	-2
Income tax expense on reclassification from AOCI included in income tax expense (benefit)	0	0	-1	1
Net income	3	-3	9	-8
Foreign Currency Translation | Amounts reclassified from AOCI, net of tax	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Net reclassification from AOCI for amortization of prior service cost included in selling and administrative expenses	0	0	5	0
Income tax expense on reclassification from AOCI included in income tax expense (benefit)	0	0	0	0
Net income	$0	$0	$5	$0

Oman_Investment_Details

Oman Investment (Details) (USD $)	Sep. 30, 2014	Jun. 30, 2012	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	USG-Zawawi Drywall LLC	Zawawi Gypsum LLC	Zawawi Gypsum LLC and USG-Zawawi Drywall LLC	Zawawi Gypsum LLC and USG-Zawawi Drywall LLC
				Co-venturer
Statement [Line Items]	'	'	'	'
Ownership percentage by parent in noncontrolling interest	50.00%	55.00%	'	'
Percentage of noncontrolling owners in VIE	50.00%	'	'	'
Loans payable and related accrued interest due to joint venture partner	'	'	'	$8
Decrease in non-controlling interest within shareholders' equity	'	'	$24	'

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Income Taxes (Textual) [Abstract]	'	'	'	'	'
Income tax expense from foreign, state and local jurisdictions	$2	'	'	'	'
Income tax expense	2	2	7	1	'
Federal net operating loss carryforwards	1,993	'	1,993	'	'
Federal alternative minimum tax credit carryforwards	45	'	45	'	'
Minimum taxable income needed to fully realize the U.S. federal net deferred tax assets	2,122	'	2,122	'	'
Foreign tax credit carryforwards	8	'	8	'	'
Deferred tax assets related to state net operating loss and tax credit carryforwards	269	'	269	'	'
Gross deferred tax assets related to state net operating loss and tax credit carry forwards that will expire in current year	11	'	11	'	'
Net operating loss and tax credit carryforwards in various foreign jurisdictions	2	'	2	'	'
Valuation allowance against deferred tax assets	961	'	961	'	995
Increase (decrease) in valuation allowance against deferred tax asset	'	'	-34	'	'
Percentage of change in ownership	'	'	50.00%	'	'
Period of change in ownership	'	'	'3 years	'	'
Long-term tax-exempt rate	3.06%	'	3.06%	'	'
Time period after the change in which amount of the limitation be increased or decreased by built-in gains or losses	'	'	'5 years	'	'
Approximate annual NOL utilization had an ownership change occurred	122	'	122	'	'
Due to state law changes	'	'	'	'	'
Income Taxes (Textual) [Abstract]	'	'	'	'	'
Increase (decrease) in valuation allowance against deferred tax asset	'	'	-11	'	'
Due to reduction in the gross value of deferred tax assets	'	'	'	'	'
Income Taxes (Textual) [Abstract]	'	'	'	'	'
Increase (decrease) in valuation allowance against deferred tax asset	'	'	-23	'	'
USG Boral Building Products	'	'	'	'	'
Income Taxes (Textual) [Abstract]	'	'	'	'	'
Withholding taxes on property contributed to equity method investment	'	'	$1	'	'

Litigation_Litigation_Details_

Litigation Litigation (Details Textual) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'	'	'	'	'
Litigation settlement accrual	$48	'	$48	'	$0
Litigation settlement charge	-48	0	-48	0	'
Accrual for probable and reasonably estimable liability for environmental cleanup	$16	'	$16	'	$18