Employee Retirement Plans - Schedule of Settlement Expense (Details) - Pension Benefits - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Settlement charge	$ 0	$ 25	$ 35
USG Corporation Pension Plan - L&W Supply
Defined Benefit Plan Disclosure [Line Items]
Settlement charge		25	26
Other income, net | USG Corporation Pension Plan - L&W Supply
Defined Benefit Plan Disclosure [Line Items]
Settlement charge		12	11
Income (loss) from discontinued operations | USG Corporation Pension Plan - L&W Supply
Defined Benefit Plan Disclosure [Line Items]
Settlement charge		13	0
Gain on sale of discontinued operations | USG Corporation Pension Plan - L&W Supply
Defined Benefit Plan Disclosure [Line Items]
Settlement charge		$ 0	$ 15