CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 111.1	$ 86.9	$ 282.3	$ 180.4
Other comprehensive (loss) income:
Net foreign currency translation adjustment	(5.0)	22.7	(25.6)	84.4
Net change in postretirement benefit plans, net of tax impacts of $1.2, $2.1, $2.0 and $3.0, respectively	3.9	3.6	6.1	5.9
Other comprehensive (loss) income	(1.1)	26.3	(19.5)	90.3
Comprehensive income	110.0	113.2	262.8	270.7
Less: Comprehensive income (loss) attributable to noncontrolling interests	0.2	0.0	0.5	(0.3)
Comprehensive income attributable to ITT Inc.	109.8	113.2	262.3	271.0
Reclassification adjustments (see Note 15):
Amortization of prior service benefit, net of tax expense of $(0.3), $(0.3), $(0.8) and $(1.3), respectively	(0.8)	(0.9)	(2.5)	(2.3)
Amortization of net actuarial loss, net of tax benefits of $0.6, $1.1, $1.9 and $3.0, respectively	1.8	2.1	5.7	5.8
Loss from plan settlement or curtailment, net of tax benefit of $0.3, $1.3, $0.3 and $1.3, respectively	(1.1)	(2.4)	(1.1)	(2.4)
Net actuarial gain, net of tax expense of $0.6, $0.0, $0.6 and $0.0, respectively	1.8	0.0	1.8	0.0
Net change in postretirement benefit plans, net of tax impacts of $1.2, $2.1, $2.0 and $3.0, respectively	$ 3.9	$ 3.6	$ 6.1	$ 5.9