Postretirement Benefit Plans - Additional Information (Detail) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) Participant shares		Dec. 31, 2020 USD ($)		Dec. 31, 2019 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Company contributions to defined contribution plans	$ 14.5		$ 10.6		$ 17.6
Shares of ITT Stock Held in Defined Contribution Plan | shares	0.1
Active participants in numerous defined benefit pension plans | Participant	950
Pension settlement charges	$ 0.0		137.0		0.0
Contributions to postretirement plans	10.5		18.0		22.9
Accumulated benefit obligation	$ 105.5		121.6
Assumed rate of future decrease in per capita cost of health care for 2028	4.50%
Employer contributions	$ 10.5		18.0
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension settlement charges	(3.4)	[1]	137.0	[1]	0.0
Contributions to postretirement plans	4.3		13.4
Defined Benefit Plan, Expected Employer Contributions Next Fiscal Year	6.0
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	6.2		4.6
Defined Benefit Plan, Expected Employer Contributions Next Fiscal Year	$ 9.0
Pre Age Sixty Five [Member]
Defined Benefit Plan Disclosure [Line Items]
Assumed rate of future increase in per capita cost of health care for 2021	6.20%
Post-age 65 retirees [Member]
Defined Benefit Plan Disclosure [Line Items]
Assumed rate of future increase in per capita cost of health care for 2021	5.60%
International Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected Benefit Obligation	86.00%
International Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension settlement charges	$ 0.0		0.1		$ 0.0
Employer contributions	3.4		4.1
U.S. Qualified Plan Termination [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, Payment for Settlement	3.4
Defined Benefit Plan, Benefit Obligation, Payment for Settlement	3.4
U.S. Qualified Plan Termination [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan Assets Used to Fund Settlement			320.0
Contributions to postretirement plans	$ 8.4		$ 8.4

[1] 2021 includes income of $3.4 from a pricing adjustment associated with the termination and sale of the U.S. qualified pension plan. In 2020, the Company recorded a settlement charge of $136.9 related to the termination and sale of the U.S. qualified pension plan.