Accounting For Income Taxes - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory tax rate	21.00%	21.00%	21.00%	21.00%	35.00%
State Tax Credit Carryforward [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Tax credit carryforward, amount	$ 17.1
Tax credit carryforwards, net of valuation allowance	7.5
Tax credit carryforward, valuation allowance	$ (9.6)
Minimum [Member] | State Tax Credit Carryforward [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Tax credit carryforward, expiration date	2022
Maximum [Member] | State Tax Credit Carryforward [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Tax credit carryforward, expiration date	2035