Litigation	6 Months Ended
Jun. 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 in the litigation 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. On behalf of this alleged direct purchaser class, the plaintiffs seek unspecified monetary damages, tripled under the antitrust laws, as well as pre-judgment interest, post-judgment interest and attorneys' fees. 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. The court has set a schedule requiring the parties in the Domestic Drywall Antitrust Litigation to complete fact discovery, primarily involving the production of documents and depositions, by October 31, 2014, and to complete expert witness discovery by March 31, 2015. 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 Inc., a subsidiary of USG Corporation, as well as other Canadian and U.S. wallboard manufacturers. As with the U.S.-based lawsuits, the plaintiffs in the Canadian lawsuits have not indicated the amount of damages that they seek. No schedule has been set for completion of pre-trial discovery in the Canadian lawsuits. USG has denied the allegations made in these wallboard pricing lawsuits. At this stage of the lawsuits, we are not able to estimate the amount, if any, of any reasonably possible loss or range of reasonably possible losses. However, based on the information known to us, we believe these 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 June 30, 2014 and December 31, 2013, we had an accrual of $17 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.

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 in the litigation 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. On behalf of this alleged direct purchaser class, the plaintiffs seek unspecified monetary damages, tripled under the antitrust laws, as well as pre-judgment interest, post-judgment interest and attorneys' fees. 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. The court has set a schedule requiring the parties in the Domestic Drywall Antitrust Litigation to complete fact discovery, primarily involving the production of documents and depositions, by October 31, 2014, and to complete expert witness discovery by March 31, 2015.

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 Inc., a subsidiary of USG Corporation, as well as other Canadian and U.S. wallboard manufacturers. As with the U.S.-based lawsuits, the plaintiffs in the Canadian lawsuits have not indicated the amount of damages that they seek. No schedule has been set for completion of pre-trial discovery in the Canadian lawsuits.

USG has denied the allegations made in these wallboard pricing lawsuits. At this stage of the lawsuits, we are not able to estimate the amount, if any, of any reasonably possible loss or range of reasonably possible losses. However, based on the information known to us, we believe these 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 June 30, 2014 and December 31, 2013, we had an accrual of $17 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.