CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 28, 2024	Sep. 30, 2023	Sep. 28, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 161.7	$ 111.8	$ 394.1	$ 321.4
Other comprehensive income (loss):
Net foreign currency translation adjustment	59.2	(30.5)	10.0	(34.7)
Net change in postretirement benefit plans, net of tax impacts of $0.6, $(0.3), $1.2, and $1.8, respectively	(1.9)	0.9	(3.6)	0.2
Other comprehensive income (loss)	57.3	(29.6)	6.4	(34.5)
Comprehensive income	219.0	82.2	400.5	286.9
Less: Comprehensive income attributable to noncontrolling interests	0.6	1.0	2.8	2.4
Comprehensive income attributable to ITT Inc.	218.4	81.2	397.7	284.5
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax [Abstract]
Amortization of prior service benefit, net of tax expense of $0.3, $0.4, $1.0, and $1.1, respectively	(1.0)	(1.1)	(3.2)	(3.4)
Amortization of net actuarial loss, net of tax benefit of $—, $(0.1), $—, and $(0.1), respectively	0.2	(0.2)	0.3	0.0
Gain on plan settlement due to divestiture, net of tax expense of $0.2, $—, $0.2, and $—	(0.8)	0.0	(0.8)	0.0
Other adjustments to postretirement benefit plans:
Net actuarial gain, net of tax expense of $0.1, $(0.6), $—, and $(0.6), respectively	(0.3)	2.2	0.1	2.2
Deferred tax asset valuation allowance reversal	0.0	0.0	0.0	1.4
Net change in postretirement benefit plans, net of tax	$ 1.9	$ (0.9)	$ 3.6	$ (0.2)