Debt - Additional Information (Detail)		1 Months Ended	3 Months Ended
	Apr. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Leverage ratio covenant period			12 months
Debt		$ 2,673,300,000	$ 2,673,300,000	$ 1,440,700,000
Maximum
Debt Instrument [Line Items]
Commitment fee percentage			0.25%
Costs and expenses incurred in connection with acquisition excluded from computation of Net Income figure used in our debt covenant calculation			$ 25,000,000.0
Debt agreement financial covenant, leverage ratio		1.00	1.00
EBITDA Ratio for Debt		3.00	3.00
Minimum
Debt Instrument [Line Items]
Commitment fee percentage			0.09%
Debt agreement financial covenant, leverage ratio		3.5	3.5
EBITDA Ratio for Debt		1.00	1.00
nVent Term Loan Facility
Debt Instrument [Line Items]
Debt term		5 years
Credit facility maximum borrowing capacity		$ 200,000,000.0	$ 200,000,000.0
Line of credit facility, amount outstanding		$ 0	0
nVent Revolving Credit Facility
Debt Instrument [Line Items]
Debt term		5 years
Credit facility maximum borrowing capacity		$ 600,000,000.0	600,000,000.0
Credit facility additional borrowing capacity		300,000,000.0	300,000,000.0
Line of credit facility, amount outstanding		0	0
Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity		2,500,000,000	2,500,000,000
Remaining availability under Credit Facility		2,220,100,000	2,220,100,000
Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Remaining availability under Credit Facility		183,400,000	183,400,000
Commercial Paper
Debt Instrument [Line Items]
Commercial Paper		257,800,000	257,800,000	34,000,000
Senior Notes | Senior Notes 3.950% Due 2023
Debt Instrument [Line Items]
Debt face amount		$ 300,000,000.0	$ 300,000,000.0
Interest rate		3.95%	3.95%
Debt		$ 300,000,000	$ 300,000,000	0
Senior Notes | Senior Notes 4.550% Due 2028
Debt Instrument [Line Items]
Debt face amount		$ 500,000,000.0	$ 500,000,000.0
Interest rate		4.55%	4.55%
Debt		$ 500,000,000	$ 500,000,000	0
Senior Notes | Senior Notes 2.900% Due 2018
Debt Instrument [Line Items]
Debt		255,300,000	255,300,000	$ 255,300,000
Other Credit Facilities
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity		31,200,000.0	31,200,000.0
Line of credit facility, amount outstanding		$ 200,000.0	$ 200,000.0
nVent Finance | Forecast
Debt Instrument [Line Items]
Excess cash threshold for payments to acquire assets	$ 50,000,000.0
nVent Finance | Forecast | nVent Term Loan Facility
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	200,000,000
nVent Finance | Forecast | nVent Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	$ 0