Leases - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Lessee Lease Description [Line Items]
Operating lease, option to extend	true
Deferred rent	$ 1.5
Lease assets	$ 27.1
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherNoncurrentAssetsMember
Short-term lease liabilities	$ 10.3
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesAndOtherLiabilities
Long-term lease liabilities	$ 18.4
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent
Operating lease rent expense	$ 10.1	$ 7.6	$ 6.1
Cash paid for operating leases	$ 11.8
Weighted average discount rate of operating leases	3.90%
Average remaining operating lease term	2 years 9 months 18 days
Operating lease liabilities, lease not yet commenced	$ 4.0
Minimum [Member]
Lessee Lease Description [Line Items]
Operating lease expiration year	2020
Maximum [Member]
Lessee Lease Description [Line Items]
Operating lease expiration year	2025
Operating lease option to extend lease term	five years
Accounting Standards Update 2016-02 [Member]
Lessee Lease Description [Line Items]
Estimated operating lease assets and liabilities to be recognized upon adoption				$ 21.6