CONSOLIDATED CONDENSED STATEMENTS OF CHANGES IN SHAREDHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]
Total shareholders' equity, beginning balance at Dec. 31, 2016	$ 1,428.4	$ 88.4	$ 1,789.2		$ 2.0
Postretirement benefit plans, beginning balance at Dec. 31, 2016				$ (145.2)
Cumulative translation adjustment, beginning balance at Dec. 31, 2016				(306.0)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Activity from stock incentive plans		0.5
Cumulative adjustment for accounting change (See Note 2)			0.5
Net income attributable to ITT Inc.	93.8		93.8
Dividends declared			(22.8)
Activity from stock incentive plans			14.8
Share repurchases		(0.9)	(31.9)
Net change in postretirement benefit plans	2.3			2.3
Net cumulative translation adjustment				61.7
Income (loss) attributable to noncontrolling interests	0.3				(0.3)
Other					(0.1)
Postretirement benefit plans, ending balance at Jun. 30, 2017				(142.9)
Cumulative translation adjustment, ending balance at Jun. 30, 2017				(244.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net change in common stock		(0.4)
Net change in retained earnings			54.4
Net change in accumulated other comprehensive loss				64.0
Net change in noncontrolling interests					(0.4)
Total shareholders' equity, ending balance at Jun. 30, 2017	1,546.0	88.0	1,843.6	(387.2)	1.6
Total shareholders' equity, beginning balance at Mar. 31, 2017	1,492.0	88.7	1,832.6		1.6
Postretirement benefit plans, beginning balance at Mar. 31, 2017				(144.1)
Cumulative translation adjustment, beginning balance at Mar. 31, 2017				(286.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Activity from stock incentive plans		0.1
Cumulative adjustment for accounting change (See Note 2)			0.0
Net income attributable to ITT Inc.	47.8		47.8
Dividends declared			(11.4)
Activity from stock incentive plans			4.3
Share repurchases		(0.8)	(29.7)
Net change in postretirement benefit plans	1.2			1.2
Net cumulative translation adjustment				42.5
Income (loss) attributable to noncontrolling interests	(0.1)				0.1
Other					(0.1)
Postretirement benefit plans, ending balance at Jun. 30, 2017				(142.9)
Cumulative translation adjustment, ending balance at Jun. 30, 2017				(244.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net change in common stock		(0.7)
Net change in retained earnings			11.0
Net change in accumulated other comprehensive loss				43.7
Net change in noncontrolling interests					0.0
Total shareholders' equity, ending balance at Jun. 30, 2017	1,546.0	88.0	1,843.6	(387.2)	1.6
Total shareholders' equity, beginning balance at Dec. 31, 2017	1,597.8	88.2	1,856.1		1.7
Postretirement benefit plans, beginning balance at Dec. 31, 2017				(137.6)
Cumulative translation adjustment, beginning balance at Dec. 31, 2017				(210.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Activity from stock incentive plans		0.5
Cumulative adjustment for accounting change (See Note 2)			(4.1)
Net income attributable to ITT Inc.	170.9		170.9
Dividends declared			(23.7)
Activity from stock incentive plans			14.4
Share repurchases		(1.1)	(54.3)
Net change in postretirement benefit plans	2.2			2.2
Net cumulative translation adjustment				(20.6)
Income (loss) attributable to noncontrolling interests	(0.3)				0.3
Other					0.0
Postretirement benefit plans, ending balance at Jun. 30, 2018				(135.4)
Cumulative translation adjustment, ending balance at Jun. 30, 2018				(231.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net change in common stock		(0.6)
Net change in retained earnings			103.2
Net change in accumulated other comprehensive loss				(18.4)
Net change in noncontrolling interests					0.3
Total shareholders' equity, ending balance at Jun. 30, 2018	1,682.3	87.6	1,959.3	(366.6)	2.0
Total shareholders' equity, beginning balance at Mar. 31, 2018	1,660.5	87.4	1,891.8		1.9
Postretirement benefit plans, beginning balance at Mar. 31, 2018				(136.5)
Cumulative translation adjustment, beginning balance at Mar. 31, 2018				(184.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Activity from stock incentive plans		0.2
Cumulative adjustment for accounting change (See Note 2)			0.0
Net income attributable to ITT Inc.	69.7		69.7
Dividends declared			(11.8)
Activity from stock incentive plans			9.7
Share repurchases		0.0	(0.1)
Net change in postretirement benefit plans	1.1			1.1
Net cumulative translation adjustment				(47.1)
Income (loss) attributable to noncontrolling interests	(0.2)				0.2
Other					(0.1)
Postretirement benefit plans, ending balance at Jun. 30, 2018				(135.4)
Cumulative translation adjustment, ending balance at Jun. 30, 2018				(231.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net change in common stock		0.2
Net change in retained earnings			67.5
Net change in accumulated other comprehensive loss				(46.0)
Net change in noncontrolling interests					0.1
Total shareholders' equity, ending balance at Jun. 30, 2018	$ 1,682.3	$ 87.6	$ 1,959.3	$ (366.6)	$ 2.0