Accounting Policies Accounting Pronouncements (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended					6 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	$ 2,101		$ 1,945				$ 6,318	$ 5,789
Operating Income (Loss)	300	$ 256	309	$ 372	$ 257	$ 629	902	938	$ 1,194	$ 1,087
Net Income (Loss) Attributable to Parent	$ 180	$ 80	$ 152	$ 163	$ 138	$ 301	$ 540	$ 453	$ 533	$ 493
Net income basic (in dollars per share)	$ 0.59	$ 0.25	$ 0.48	$ 0.51	$ 0.43	$ 0.94	$ 1.74	$ 1.42	$ 1.68	$ 1.49
Net income diluted (in dollars per share)	$ 0.58	$ 0.25	$ 0.48	$ 0.51	$ 0.43	$ 0.93	$ 1.73	$ 1.41	$ 1.66	$ 1.48
Plumbing Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	$ 992		$ 950				$ 2,995	$ 2,771
Decorative Architectural Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	673		562				2,024	1,719
Cabinetry Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	239		229				724	711
Windows and Other Specialty Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	197		204				575	588
Operating Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	2,101	$ 1,853	1,945	$ 2,066	$ 1,778	$ 3,844	6,318	5,789	$ 7,642	$ 7,361
Operating Income (Loss)	320	277	331	398	280	678	962	1,009	1,286	1,181
Operating Segments | Plumbing Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	992	961	950	949	872	1,821	2,995	2,771	3,732	3,529
Operating Income (Loss)	177	165	175	200	162	362	534	537	702	654
Operating Segments | Decorative Architectural Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	673	487	562	661	496	1,157	2,024	1,719	2,206	2,092
Operating Income (Loss)	104	83	112	149	94	243	338	355	438	433
Operating Segments | Cabinetry Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	239	223	229	251	231	482	724	711	934	970
Operating Income (Loss)	23	25	20	31	16	47	62	67	92	97
Operating Segments | Windows and Other Specialty Products
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	197	182	204	205	179	384	575	588	770	770
Operating Income (Loss)	16	4	24	18	8	26	28	50	54	(3)
Corporate, Non-Segment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Expenses	$ (20)	(21)	(22)	(26)	23	(49)	$ (60)	(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 basic (in dollars per share)		$ 0.28	$ 0.47	$ 0.50	$ 0.44	$ 0.93		$ 1.40	$ 1.68	$ 1.49
Net income diluted (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)