LIFO to FIFO Change in Accounting Principle - OCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 29, 2025	Mar. 30, 2024
Net income	$ 109.1	$ 112.5
Comprehensive income	135.2	79.4
Comprehensive income attributable to ITT Inc.	$ 134.5	78.4
Previously Reported
Net income		112.0
Comprehensive income		78.9
Comprehensive income attributable to ITT Inc.		77.9
Revision of Prior Period, Adjustment
Net income		0.5
Comprehensive income		0.5
Comprehensive income attributable to ITT Inc.		$ 0.5