CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 03, 2021	Jun. 27, 2020	Jul. 03, 2021	Jun. 27, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 39.2	$ 48.0	$ 125.7	$ 133.1
Other comprehensive income (loss):
Net foreign currency translation adjustment	8.4	2.1	(21.6)	(49.2)
Net change in postretirement benefit plans, net of tax (expense) benefit of $(0.1), $0.3, $(0.2), and $0.6, respectively	0.0	0.9	0.0	1.8
Other comprehensive income (loss)	8.4	3.0	(21.6)	(47.4)
Comprehensive income	47.6	51.0	104.1	85.7
Less: Comprehensive income attributable to noncontrolling interests	0.2	0.0	0.5	0.3
Comprehensive income attributable to ITT Inc.	47.4	51.0	103.6	85.4
Reclassification adjustments (see Note 15):
Amortization of prior service benefit, net of tax expense of $(0.3), $(0.3), $(0.6) and $(0.6), respectively	(0.9)	(1.0)	(1.9)	(1.9)
Amortization of net actuarial loss, net of tax benefit of $0.2, $0.6, $0.4 and $1.2, respectively	0.9	1.9	1.9	3.7
Net change in postretirement benefit plans, net of tax (expense) benefit of $(0.1), $0.3, $(0.2), and $0.6, respectively	$ 0.0	$ 0.9	$ 0.0	$ 1.8