Income taxes - Deferred tax assets and liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Tax loss and credit carryforwards	$ 180,782	$ 174,997
Lease assets	25,429	28,577
Pension	12,237	14,971
Reserves and accruals	72,931	60,799
Other	7,996	3,207
Less: valuation allowances	(155,008)	(119,233)
Total deferred tax assets	144,367	163,318
Deferred tax liabilities:
Property, plant and equipment	25,633	23,053
Intangibles — stock acquisitions	476,150	441,079
Unremitted non-U.S. earnings	91,539	81,967
Lease liabilities	25,429	28,577
Other	2,221	22,628
Total deferred tax liabilities	620,972	597,304
Net deferred tax liability	$ (476,605)	$ (433,986)