Retirement Plan - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan matching contributions amount	$ 5.1	$ 3.5	$ 2.3
First Eligible Employee Percentage
Defined Benefit Plan Disclosure [Line Items]
Companies matching on eligible employee contribution percentage	100.00%	100.00%	100.00%
Defined benefit plan eligible employee percentage	3.00%	3.00%	3.00%
Second Eligible Employee Percentage
Defined Benefit Plan Disclosure [Line Items]
Companies matching on eligible employee contribution percentage	50.00%	50.00%	50.00%
Defined benefit plan eligible employee percentage	2.00%	2.00%	2.00%