Change in Accounting Principle - LIFO to FIFO (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Organization And Summary Of Significant Accounting Policies [Line Items]
Costs of revenue	$ 2,546.1	$ 2,381.3	$ 2,173.4
Gross profit	1,392.4	1,249.4	1,109.6
Operating income	684.5	678.1	530.5
Income (Loss) Attributable to Parent, before Tax		649.7	521.8
Effective tax rate	160.1	126.3	105.4
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	491.4	523.4	416.4
Net income	491.3	523.3	415.5
Net income attributable to ITT Inc.	488.0	519.9	412.2
Income from continuing operations, net of tax	$ 488.1	$ 520.0	$ 413.1
Income (Loss) from Continuing Operations, Per Basic Share	$ 6.15	$ 6.36	$ 5.02
Net Income (Loss) Available to Common Stockholders, Basic	6.15	6.36	5.01
Continuing operations	6.11	6.32	5.00
Earnings Per Share, Diluted	$ 6.11	$ 6.32	$ 4.98
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 607.1	$ 436.9	$ 427.9
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	603.8	433.5	424.6
Change in inventories	(24.6)	0.0	(36.7)
Increase (Decrease) in Accrued and Deferred Income Taxes		(1.6)	6.0
Inventory, Gross		612.3
Assets, Current	3,354.3	1,885.8
Other non-current assets	385.3	384.1
Assets, Noncurrent	2,956.1	2,845.5
Assets	6,310.4	4,731.3
Other non-current liabilities	279.3	260.7
Liabilities, Noncurrent	920.8	612.3
Liabilities	2,219.1	1,945.5
Retained earnings	2,987.1	3,115.6
Stockholders' Equity Attributable to Parent	4,084.4	2,778.8
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	4,091.3	2,785.8	2,553.7	$ 2,270.3
Liabilities and Equity	$ 6,310.4	4,731.3
Previously Reported
Organization And Summary Of Significant Accounting Policies [Line Items]
Costs of revenue		2,383.4	2,175.7
Gross profit		1,247.3	1,107.3
Operating income		676.0	528.2
Income (Loss) Attributable to Parent, before Tax		647.6	519.5
Effective tax rate		125.8	104.8
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		521.8	414.7
Net income		521.7	413.8
Net income attributable to ITT Inc.		518.3	410.5
Income from continuing operations, net of tax		$ 518.4	$ 411.4
Income (Loss) from Continuing Operations, Per Basic Share		$ 6.34	$ 5.00
Net Income (Loss) Available to Common Stockholders, Basic		6.34	4.99
Continuing operations		6.30	4.97
Earnings Per Share, Diluted		$ 6.30	$ 4.96
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		$ 435.3	$ 426.2
Comprehensive Income (Loss), Net of Tax, Attributable to Parent		431.9	422.9
Change in inventories		2.0	(34.4)
Increase (Decrease) in Accrued and Deferred Income Taxes		(2.1)	5.4
Inventory, Gross		591.2
Assets, Current		1,864.7
Other non-current assets		384.6
Assets, Noncurrent		2,846.0
Assets		4,710.7
Other non-current liabilities		256.3
Liabilities, Noncurrent		607.9
Liabilities		1,941.1
Retained earnings		3,099.4
Stockholders' Equity Attributable to Parent		2,762.6
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		2,769.6		$ 2,257.4
Liabilities and Equity		4,710.7
Revision of Prior Period, Adjustment
Organization And Summary Of Significant Accounting Policies [Line Items]
Costs of revenue		(2.1)	(2.3)
Gross profit		2.1	2.3
Operating income		2.1	2.3
Income (Loss) Attributable to Parent, before Tax		2.1	2.3
Effective tax rate		0.5	0.6
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		1.6	1.7
Net income		1.6	1.7
Net income attributable to ITT Inc.		1.6	1.7
Income from continuing operations, net of tax		$ 1.6	$ 1.7
Income (Loss) from Continuing Operations, Per Basic Share		$ 0.02	$ 0.02
Net Income (Loss) Available to Common Stockholders, Basic		0.02	0.02
Continuing operations		0.02	0.03
Earnings Per Share, Diluted		$ 0.02	$ 0.02
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		$ 1.6	$ 1.7
Comprehensive Income (Loss), Net of Tax, Attributable to Parent		1.6	1.7
Change in inventories		(2.0)	(2.3)
Increase (Decrease) in Accrued and Deferred Income Taxes		0.5	0.6
Inventory, Gross		21.1	19.1
Assets, Current		21.1
Other non-current assets		(0.5)
Assets, Noncurrent		(0.5)
Assets		20.6
Other non-current liabilities		4.4
Liabilities, Noncurrent		4.4
Liabilities		4.4
Retained earnings		16.2	$ 14.6
Stockholders' Equity Attributable to Parent		16.2
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		16.2
Liabilities and Equity		$ 20.6