GOODWILL AND OTHER INTANGIBLE ASSETS - Goodwill Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Goodwill [Line Items]
Balance at beginning of period			$ 1,932
Impairment charge	$ 0	$ 0	944	$ 0
Divestiture			4
Foreign currency translation			(18)
Balance at end of period	966		966
Composites
Goodwill [Line Items]
Balance at beginning of period			57
Impairment charge			0
Divestiture			0
Foreign currency translation			(1)
Balance at end of period	56		56
Insulation
Goodwill [Line Items]
Balance at beginning of period			1,479
Impairment charge			944
Divestiture			4
Foreign currency translation			(17)
Balance at end of period	514		514
Roofing
Goodwill [Line Items]
Balance at beginning of period			396
Impairment charge			0
Divestiture			0
Foreign currency translation			0
Balance at end of period	$ 396		$ 396