Income Tax Expense - NOL and Tax Credit Carryforwards (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Federal
NOL and Tax Credit Carryforwards [Line Items]
Tax Credit Carryforwards	$ 480,400,000	$ 464,500,000
Federal Capital Loss Carryforwards	0	35,100,000
Valuation allowance	0
State
NOL and Tax Credit Carryforwards [Line Items]
Tax Credit Carryforwards	21,500,000	24,500,000
NOL Carryforwards	280,900,000	323,000,000.0
State Capital Loss Carryforwards	0	83,200,000
Valuation allowance	55,400,000	59,600,000
Valuation allowance	$ 10,500,000
State | Capital Loss Carryforward
NOL and Tax Credit Carryforwards [Line Items]
Valuation allowance		$ 58,700,000