Equity Method Investments - Balance Sheet (Details) - USG Boral Building Products - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Current assets	$ 368	$ 446
Non-current assets	935	989
Current liabilities	197	245
Long-term debt	40	46
Other non-current liabilities	17	21
Shareholders' equity	1,049	1,123
Current portion of long-term debt	16	35
Shareholders' equity related to non-controlling interests	$ 60	$ 70