Fair Value Measurements - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020 USD ($) item Liability	Dec. 31, 2019 USD ($) Liability	Dec. 31, 2017 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Number of counterparties, which experienced significant downgrades | item	0
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value measurement with unobservable inputs reconciliation, number of liabilities | Liability	1	1
Level 3 | Acquisition of Oxford Performance Materials, Inc.
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Acquisition of fair value liabilities, contingent consideration	$ 3,300,000	$ 3,100,000	$ 2,900,000
Level 2 | Fair Value Measured on Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets	18,400,000	4,300,000
Derivative liabilities	14,800,000	21,700,000
Level 2 | Fair Value Measured on Recurring Basis | Interest Rate Swap Agreements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative liabilities	$ 0	$ 600,000
Derivative Liability, Measurement Input [Extensible List]	hxl:MeasurementInputLIBORYieldCurveMember	hxl:MeasurementInputLIBORYieldCurveMember
Level 2 | Fair Value Measured on Recurring Basis | Foreign Currency Forward Exchange Contracts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets	$ 16,000,000.0	$ 4,300,000
Derivative Asset, Measurement Input [Extensible List]	us-gaap:MeasurementInputQuotedPriceMember	us-gaap:MeasurementInputQuotedPriceMember
Derivative liabilities	$ 2,600,000	$ 15,700,000
Derivative Liability, Measurement Input [Extensible List]	us-gaap:MeasurementInputQuotedPriceMember	us-gaap:MeasurementInputQuotedPriceMember
Level 2 | Fair Value Measured on Recurring Basis | Commodity Swap Agreements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets	$ 2,200,000
Derivative Asset, Measurement Input [Extensible List]	us-gaap:MeasurementInputQuotedPriceMember
Derivative liabilities	$ 1,100,000	$ 5,400,000
Derivative Liability, Measurement Input [Extensible List]	us-gaap:MeasurementInputQuotedPriceMember	us-gaap:MeasurementInputQuotedPriceMember
Level 2 | Fair Value Measured on Recurring Basis | Cross Currency and Interest Rate Swap
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets	$ 300,000	$ 0
Derivative Asset, Measurement Input [Extensible List]	hxl:USDSecuredOvernightFinancingRateCurvesMember	hxl:USDSecuredOvernightFinancingRateCurvesMember
Derivative liabilities	$ 11,100,000	$ 0
Derivative Liability, Measurement Input [Extensible List]	hxl:USDSecuredOvernightFinancingRateCurvesMember	hxl:USDSecuredOvernightFinancingRateCurvesMember