LIFO to FIFO Change in Accounting Principle - Balance Sheet (Details) - USD ($) $ in Millions	Mar. 29, 2025	Dec. 31, 2024	Mar. 30, 2024	Dec. 31, 2023
Inventories		$ 612.3
Total current assets	$ 1,964.4	1,885.8
Other non-current assets	379.5	384.1
Total non-current assets	2,869.3	2,845.5
Total assets	4,833.7	4,731.3
Other non-current liabilities	267.1	260.7
Total non-current liabilities	392.0	612.3
Total liabilities	2,047.9	1,945.5
Retained earnings	3,090.5	3,115.6
Total ITT Inc. shareholders’ equity	2,779.3	2,778.8
Total shareholders’ equity	2,785.8	2,785.8	$ 2,601.3	$ 2,553.7
Total liabilities and shareholders’ equity	$ 4,833.7	4,731.3
Previously Reported
Inventories		591.2
Total current assets		1,864.7
Other non-current assets		384.6
Total non-current assets		2,846.0
Total assets		4,710.7
Other non-current liabilities		256.3
Total non-current liabilities		607.9
Total liabilities		1,941.1
Retained earnings		3,099.4
Total ITT Inc. shareholders’ equity		2,762.6
Total shareholders’ equity		2,769.6		2,539.1
Total liabilities and shareholders’ equity		4,710.7
Revision of Prior Period, Adjustment
Inventories		21.1		19.1
Total current assets		21.1
Other non-current assets		(0.5)
Total non-current assets		(0.5)
Total assets		20.6
Other non-current liabilities		4.4
Total non-current liabilities		4.4
Total liabilities		4.4
Retained earnings		16.2		$ 14.6
Total ITT Inc. shareholders’ equity		16.2
Total shareholders’ equity		16.2
Total liabilities and shareholders’ equity		$ 20.6