Financial instruments - Schedule of foreign exchange gains and losses recognized within AOCI and the interest benefit recognized within interest expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Foreign currency translation adjustments, net of tax of $(5,563), $6,442 and $(6,270), respectively	$ (63,191)	$ 59,758	$ 4,195
Interest benefit on swaps not designed as hedging instrument	19,296	19,178	$ 18,866
Cross Currency Interest Rate Contract | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Interest benefit on swaps not designed as hedging instrument	19,296	14,488
Cross Currency Interest Rate Contract | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Foreign currency translation adjustments, net of tax of $(5,563), $6,442 and $(6,270), respectively	$ 34,849	$ 37,312