Accounting Policies Accounting Pronouncements (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended					6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	$ 2,297			$ 2,066		$ 4,217	$ 3,844
Operating Income (Loss)	358	$ 256	$ 309	372	$ 257	602	629	$ 938	$ 1,194	$ 1,087
Net Income (Loss) Attributable to Parent	$ 211	$ 80	$ 152	$ 163	$ 138	$ 360	$ 301	$ 453	$ 533	$ 493
Net income (in dollars per share)	$ 0.69	$ 0.25	$ 0.48	$ 0.51	$ 0.43	$ 1.16	$ 0.94	$ 1.42	$ 1.68	$ 1.49
Net income (in dollars per share)	$ 0.68	$ 0.25	$ 0.48	$ 0.51	$ 0.43	$ 1.15	$ 0.93	$ 1.41	$ 1.66	$ 1.48
Plumbing Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	$ 1,032			$ 949		$ 2,003	$ 1,821
Decorative Architectural Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	806			661		1,351	1,157
Cabinetry Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	268			251		485	482
Windows and Other Specialty Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	191			205		378	384
Operating Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	2,297	$ 1,853	$ 1,945	2,066	$ 1,778	4,217	3,844	$ 5,789	$ 7,642	$ 7,361
Operating Income (Loss)	380	277	331	398	280	642	678	1,009	1,286	1,181
Operating Segments | Plumbing Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	1,032	961	950	949	872	2,003	1,821	2,771	3,732	3,529
Operating Income (Loss)	194	165	175	200	162	357	362	537	702	654
Operating Segments | Decorative Architectural Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	806	487	562	661	496	1,351	1,157	1,719	2,206	2,092
Operating Income (Loss)	145	83	112	149	94	234	243	355	438	433
Operating Segments | Cabinetry Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	268	223	229	251	231	485	482	711	934	970
Operating Income (Loss)	33	25	20	31	16	39	47	67	92	97
Operating Segments | Windows and Other Specialty Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	191	182	204	205	179	378	384	588	770	770
Operating Income (Loss)	8	4	24	18	8	12	26	50	54	(3)
Corporate, Non-Segment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Expenses	$ (22)	(21)	(22)	(26)	23	$ (40)	(49)	(71)	(92)	(94)
Previous Accounting Guidance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Income (Loss)		264	295	357	253		610	905	1,169	1,053
Net Income (Loss) Attributable to Parent		$ 87	$ 148	$ 158	$ 140		$ 298	$ 446	$ 533	$ 491
Net income (in dollars per share)		$ 0.28	$ 0.47	$ 0.50	$ 0.44		$ 0.93	$ 1.40	$ 1.68	$ 1.49
Net income (in dollars per share)		$ 0.27	$ 0.46	$ 0.49	$ 0.43		$ 0.92	$ 1.38	$ 1.66	$ 1.47
Previous Accounting Guidance | Operating Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales		$ 1,874	$ 1,936	$ 2,057	$ 1,777		$ 3,834	$ 5,770	$ 7,644	$ 7,357
Operating Income (Loss)		287	321	387	279		666	987	1,274	1,162
Previous Accounting Guidance | Operating Segments | Plumbing Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales		972	951	949	863		1,812	2,763	3,735	3,526
Operating Income (Loss)		169	175	198	156		354	529	698	642
Previous Accounting Guidance | Operating Segments | Decorative Architectural Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales		494	553	653	505		1,158	1,711	2,205	2,092
Operating Income (Loss)		88	104	141	101		242	346	434	430
Previous Accounting Guidance | Operating Segments | Cabinetry Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales		223	229	251	231		482	711	934	970
Operating Income (Loss)		25	19	30	16		46	65	90	93
Previous Accounting Guidance | Operating Segments | Windows and Other Specialty Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales		185	203	204	178		382	585	770	769
Operating Income (Loss)		5	23	18	6		24	47	52	(3)
Previous Accounting Guidance | Corporate, Non-Segment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Expenses		$ (23)	$ (26)	$ (30)	$ (26)		$ (56)	$ (82)	$ (105)	$ (109)