CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Oct. 01, 2022	Sep. 30, 2023	Oct. 01, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 111.8	$ 103.2	$ 321.4	$ 253.3
Other comprehensive (loss):
Net foreign currency translation adjustment	(30.5)	(44.6)	(34.7)	(127.1)
Net change in postretirement benefit plans, net of tax impacts of $(0.3), $(3.4), $1.8 and $(3.1), respectively	0.9	11.4	0.2	10.9
Other comprehensive (loss)	(29.6)	(33.2)	(34.5)	(116.2)
Comprehensive income	82.2	70.0	286.9	137.1
Less: Comprehensive income attributable to noncontrolling interests	1.0	0.8	2.4	1.5
Comprehensive income attributable to ITT Inc.	81.2	69.2	284.5	135.6
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax [Abstract]
Amortization of prior service benefit, net of tax expense of $0.4, $0.3, $1.1 and $0.9, respectively	(1.1)	(1.1)	(3.4)	(3.0)
Amortization of net actuarial loss, net of tax benefit (expense) of $0.1, $(0.1), $0.1 and $(0.4), respectively	(0.2)	0.7	0.0	2.1
Other Adjustments [Abstract]
Deferred tax asset valuation allowance reversal	0.0	0.0	1.4	0.0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	2.2	5.7	2.2	5.7
Prior service credit, net of tax expense of $—, $(1.9), $—, and $(1.9), respectively	0.0	6.1	0.0	6.1
Net change in postretirement benefit plans, net of tax	$ (0.9)	$ (11.4)	$ (0.2)	$ (10.9)