Financial instruments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) Financial_Institution_Counterparty	Dec. 31, 2018 USD ($) Financial_Institution_Counterparty	Dec. 31, 2019 EUR (€) Financial_Institution_Counterparty	Dec. 31, 2018 EUR (€) Financial_Institution_Counterparty
Derivatives Fair Value [Line Items]
Foreign currency translation, continuing operations, adjustment gain (loss), net of tax	$ 59,758,000	$ 4,195,000	$ (83,889,000)
Interest benefit on swaps not designed as hedging instrument	19,178,000	18,866,000	3,277,000
Cash Flow Hedging
Derivatives Fair Value [Line Items]
Ineffectiveness on hedging derivatives	0	0	0
Cross Currency Interest Rate Contract | Cash Flow Hedging
Derivatives Fair Value [Line Items]
Foreign currency translation, continuing operations, adjustment gain (loss), net of tax	(37,300,000)	20,800,000
Not Designated as Hedging Instrument | Foreign Currency Exchange Contracts
Derivatives Fair Value [Line Items]
Loss on derivative	1,800,000	3,800,000
Total notional amount for all open foreign currency forward contracts	163,500,000	145,100,000
Not Designated as Hedging Instrument | Cross Currency Interest Rate Contract
Derivatives Fair Value [Line Items]
Interest benefit on swaps not designed as hedging instrument	14,500,000	18,900,000
Designated as Hedging Instrument | Foreign Currency Exchange Contracts | Cash Flow Hedging
Derivatives Fair Value [Line Items]
Total notional amount for all open foreign currency forward contracts	$ 129,500,000	132,000,000.0
Designated as Hedging Instrument | Cross Currency Interest Rate Contract
Derivatives Fair Value [Line Items]
Total notional amount for all open foreign currency forward contracts		$ 250,000,000	$ 500,000,000	€ 219,200,000	€ 433,900,000
Derivative, number of instruments held | Financial_Institution_Counterparty		5	6	5	6
Derivative, fixed interest rate		4.875%	4.625%	4.875%	4.625%
Derivative, annual interest rate		2.4595%	1.942%	2.4595%	1.942%