Employee Retirement Plans - Textuals (Details) - USD ($) $ in Millions		1 Months Ended	12 Months Ended
	Jan. 01, 2014	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation			$ 1,354	$ 1,429
Minimum funded percentage of ABO			100.00%
Defined Contribution Plans Disclosure [Abstract]
Total charges for defined contribution plans			$ 7	6	$ 3
Minimum contribution percentage			1.00%
Maximum contribution percentage			75.00%
Employees earned a guaranteed company on contributions (as a percent)	25.00%				10.00%
Employees earned a guaranteed company match on eligible compensation (up to) (as a percent)	6.00%				6.00%
Vested period company matching contributions for employee			3 years
USG Corporation Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Settlement charge		$ 15
Pension
Defined Benefit Plan Disclosure [Line Items]
Settlement charge			$ 1	13	$ 16
Actuarial gain			$ 119	$ (327)
Weighted-average discount rate		4.90%	4.43%	4.10%	4.90%
Net actuarial loss			$ 19
Prior service cost (credit)			$ 0
Expected return on plan assets (as a percent)			6.70%	7.00%
Estimated future employer benefit plan contribution			$ 65
Expected future benefit payments in next twelve months			105
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Actuarial gain			$ 14	$ (4)
Weighted-average discount rate			4.24%	3.70%
Net actuarial loss			$ 1
Prior service cost (credit)			(28)
Expected future benefit payments in next twelve months			$ 9
U.S. Postretirement Health Care Plan
Defined Benefit Plan Disclosure [Line Items]
Annual increase to contributions health care cost (as a percent)			3.00%
Canadian Postretirement Health Care Plan
Defined Benefit Plan Disclosure [Line Items]
Assumed health care cost trend rate			8.00%	8.25%
Ultimate health care cost trend rate			4.00%	4.00%