Postretirement Benefit Plans - Additional Information (Detail) shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2016 USD ($) Employees Participant shares		Dec. 31, 2015 USD ($)		Dec. 31, 2014 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Company contributions to defined contribution plans		$ 17.3		$ 18.4		$ 17.3
Shares of ITT Stock Held in Defined Contribution Plan | shares		0.2
Active participants in numerous defined benefit pension plans | Participant		2,100
Accumulated benefit obligation		$ 389.4		415.4
Number of Employees Offered a Pension Settlement | Employees		1,100
Defined Benefit Plan, Settlements, Plan Assets		$ 28.5		1.1
Defined Benefit Plan, Settlements, Benefit Obligation		$ 26.6	[1]	$ 1.1
Assumed rate of future decrease in per capita cost of health care for 2021		4.50%
Effect of one percent increase on benefit obligation		$ 7.4
Effect of one percent increase on annual service and interest cost components		0.3
Effect of one percent decrease on benefit obligation		6.3
Effect of one percent decrease on annual service and interest cost components		$ 0.3
Reduction to Investment Target Allocation for Fixed Income		15.00%
Long-term annual rate of return for domestic pension plans		7.20%		8.00%		8.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-Term Return on Assets, Estimate for Next Year		7.00%
Contributions to postretirement plans		$ 19.0		$ 18.6		$ 12.6
Employer contributions		$ 19.0		18.6
Consolidated Hourly Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected Benefit Obligation		41.00%
Other Non Qualified Us Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected Benefit Obligation		4.00%
Pension Plan For Bargaining Unit Employees Seneca Falls [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected Benefit Obligation		35.00%
International Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected Benefit Obligation		20.00%
Effect of settlement, curtailment, or special termination benefit(a)		$ 0.0		0.1		0.4
Defined Benefit Plan, Settlements, Plan Assets		0.5		1.1
Defined Benefit Plan, Settlements, Benefit Obligation		$ 0.5		$ 1.1
Long-term annual rate of return for domestic pension plans		4.80%		4.80%
Employer contributions		$ 3.2		$ 3.8
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect of settlement, curtailment, or special termination benefit(a)		0.0		(4.2)	[2]	0.0
Defined Benefit Plan, Settlements, Plan Assets		0.0		0.0
Defined Benefit Plan, Settlements, Benefit Obligation		$ 0.0		$ 0.0
Long-term annual rate of return for domestic pension plans		7.20%		8.00%
Defined Benefit Plan, Expected Employer Contributions Next Fiscal Year		$ 9.0
Employer contributions		6.2		$ 6.2
U.S. Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect of settlement, curtailment, or special termination benefit(a)		12.7	[1]	0.0		0.0
Defined Benefit Plan, Settlements, Plan Assets		28.0	[1]	0.0
Defined Benefit Plan, Settlements, Benefit Obligation		$ 28.0	[1]	$ 0.0
Long-term annual rate of return for domestic pension plans		7.20%		8.00%
Employer contributions		$ 9.6		$ 8.6
Actuarial Loss on Pension Settlement [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Settlements, Benefit Obligation	[1]	$ 1.4
Pre-age 65 retirees [Member]
Defined Benefit Plan Disclosure [Line Items]
Assumed rate of future increase in per capita cost of health care for 2013		7.50%
Post-age 65 retirees [Member]
Defined Benefit Plan Disclosure [Line Items]
Assumed rate of future increase in per capita cost of health care for 2013		7.00%
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect of settlement, curtailment, or special termination benefit(a)		$ 12.7		0.1		$ 0.4
Contributions to postretirement plans		12.8		12.4
Discretionary Pension Contribution		7.8		$ 7.5
Defined Benefit Plan, Expected Employer Contributions Next Fiscal Year		$ 4.0

[1] (a)During 2016, we recognized a non-cash pretax pension settlement charge of $12.7 as the result of a program offering certain former U.S. employees with a vested pension benefit an option to take a one-time lump sum distribution as part of ITT's overall plan to de-risk its pension plans. Approximately 1,100 participants accepted the offer, resulting in a payment of $28.0 from the plan and a reduction in the Company's projected benefit obligation of $26.6, including an actuarial loss of $1.4.

[2] (b)During 2015, we recognized a benefit of $4.2 from a curtailment gain related to a reduction in force in our ICS segment.