Commitments - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments Disclosure [Line Items]
Rent expense	$ 89,377	$ 68,920	$ 62,294
Short term committed purchase obligations	49,912
Contribution by employer for employee saving plan	$ 19,600	$ 18,210	$ 9,681
Buildings
Commitments Disclosure [Line Items]
Terms of operating leases expiring year	Dec. 31, 2032
Land
Commitments Disclosure [Line Items]
Terms of operating leases expiring year	Dec. 31, 2057