Income taxes - Reconciliations between statutory federal income tax rate and effective income tax rate (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal statutory rate	21.00%	21.00%	21.00%
Tax effect of international items	(6.00%)	(5.30%)	(11.30%)
Legal entity merger - deferred taxes	0.00%	0.00%	(38.00%)
Excess tax benefits related to share-based compensation	(1.10%)	(4.90%)	(4.50%)
State taxes, net of federal benefit	0.10%	(0.30%)	(4.90%)
Uncertain tax contingencies	(0.10%)	(0.50%)	0.00%
Contingent consideration	0.20%	(2.20%)	3.40%
Intellectual property impairment charge	0.00%	(1.20%)	0.00%
Research and development tax credit	(0.80%)	(1.10%)	(1.10%)
Other, net	0.00%	0.60%	(0.50%)
Effective income tax rate, total	13.30%	6.10%	(35.90%)
Increase (decrease) in deferred tax liability due to merger of foreign subsidiaries			$ (129.0)