Oman Investment (Details)	Jun. 30, 2015	Jun. 30, 2012
USG-Zawawi Drywall LLC
Statement [Line Items]
Ownership percentage by parent in noncontrolling interest	50.00%
Percentage of noncontrolling owners in VIE	50.00%
Zawawi Gypsum LLC
Statement [Line Items]
Ownership percentage by parent in noncontrolling interest		55.00%