Basis of Presentation and Summary of Significant Accounting Policies - Revenue, Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Impairment losses on contract assets	$ 0	$ 0
Operating Lease, Right-of-Use Asset	77,200,000	0
Operating Lease, Liability, Current	19,000,000.0	0
Operating Lease, Liability, Noncurrent	$ 61,100,000	$ 0
Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenues, percent	92.00%	92.50%	92.40%
Transferred over Time
Disaggregation of Revenue [Line Items]
Revenues, percent	8.00%	7.50%	7.60%