ACCOUNTING POLICIES - Recently Issued Accounting Pronouncements (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	$ 2,041	$ 2,101	$ 2,297	$ 1,920	$ 1,853	$ 1,945	$ 2,066	$ 1,778	$ 8,359	$ 7,642	$ 7,361
Operating Profit (Loss)									1,211	1,194	1,087
Net income attributable to Masco Corporation	$ 194	$ 180	$ 211	$ 149	$ 80	$ 152	$ 163	$ 138	$ 734	$ 533	$ 493
Income per common share attributable to Masco Corporation:
Net income, basic (in dollars per share)	$ 0.65	$ 0.59	$ 0.69	$ 0.48	$ 0.25	$ 0.48	$ 0.51	$ 0.43	$ 2.38	$ 1.68	$ 1.49
Net income, diluted (in dollars per share)	$ 0.64	$ 0.58	$ 0.68	$ 0.47	$ 0.25	$ 0.48	$ 0.51	$ 0.43	$ 2.37	$ 1.66	$ 1.48
Recently Issued Accounting Pronouncements
Reclassification from AOCI, Current Period, Tax				$ 59
Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales										$ (2)	$ 4
Operating Profit (Loss)										(1)	2
Accounting Standards Update 2017-07
Recently Issued Accounting Pronouncements
Non-operating income (expense), expected to be adjusted										26	32
Previous Accounting Guidance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Profit (Loss)										1,169	1,053
Net income attributable to Masco Corporation										$ 533	$ 491
Income per common share attributable to Masco Corporation:
Net income, basic (in dollars per share)										$ 1.68	$ 1.49
Net income, diluted (in dollars per share)										$ 1.66	$ 1.47
Plumbing Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales									$ 3,998	$ 3,732	$ 3,529
Decorative Architectural Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales									2,656	2,206	2,092
Cabinetry Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales									950	934	970
Windows and Other Specialty Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales									755	770	770
Operating Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales									8,359	7,642	7,361
Operating Profit (Loss)									1,291	1,286	1,181
Operating Segments | Previous Accounting Guidance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales										7,644	7,357
Operating Profit (Loss)										1,274	1,162
Operating Segments | Plumbing Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales									3,998	3,732	3,529
Operating Profit (Loss)									715	702	654
Operating Segments | Plumbing Products | Previous Accounting Guidance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales										3,735	3,526
Operating Profit (Loss)										698	642
Operating Segments | Decorative Architectural Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales									2,656	2,206	2,092
Operating Profit (Loss)									456	438	433
Operating Segments | Decorative Architectural Products | Previous Accounting Guidance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales										2,205	2,092
Operating Profit (Loss)										434	430
Operating Segments | Cabinetry Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales									950	934	970
Operating Profit (Loss)									86	92	97
Operating Segments | Cabinetry Products | Previous Accounting Guidance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales										934	970
Operating Profit (Loss)										90	93
Operating Segments | Windows and Other Specialty Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales									755	770	770
Operating Profit (Loss)									34	54	(3)
Operating Segments | Windows and Other Specialty Products | Previous Accounting Guidance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales										770	769
Operating Profit (Loss)										52	(3)
Corporate, Non-Segment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
General corporate expense, net									$ (80)	(92)	(94)
Corporate, Non-Segment | Previous Accounting Guidance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
General corporate expense, net										$ (105)	$ (109)