Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Income Tax Disclosure [Line Items]
Effective tax rate	6.20%	3.80%
Income tax rate at federal statutory rates	21.00%	21.00%
Federal Tax Credit Carry Forwards [Member]
Income Tax Disclosure [Line Items]
Deferred tax assets, valuation allowance	$ 1.2	$ 1.2	$ 39.5
State Tax Credit Carry Forwards [Member]
Income Tax Disclosure [Line Items]
Deferred tax assets, valuation allowance	12.8	12.8	15.0
Federal Tax Credits [Member]
Income Tax Disclosure [Line Items]
Deferred tax assets, valuation allowance	2.9	2.9	7.1
Charitable Contribution [Member]
Income Tax Disclosure [Line Items]
Deferred tax assets, valuation allowance	$ 4.6	$ 4.6	$ 4.0