Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Employee Benefit Plan [Abstract]
Matching contributions amount	$ 1.6	$ 1.6	$ 0.6
Total contributions to multi-employer plans	$ 0.9	$ 0.8	$ 0.8
Maximum Contribution of total contributions for multi-employer pension plans	5.00%