Income taxes - Summary of U.S. and non-U.S. components of income from continuing operations before taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S.	$ 233,034	$ 89,021	$ 37,201
Non-U.S.	124,698	250,882	182,427
Income from continuing operations before taxes	$ 357,732	$ 339,903	$ 219,628