Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Income Taxes
Valuation allowance, deferred tax asset, increase (decrease), amount	$ 50.6	$ 50.6
States operating loss carryforwards	$ 199.0
Minimum
Income Taxes
Number of tax years open for state tax audit (in years)	3 years
Maximum
Income Taxes
Number of tax years open for state tax audit (in years)	5 years
Domestic Tax Authority
Income Taxes
Operating loss carryforwards	$ 1,600.0
Operating loss carryforwards, subject to expiration	700.0
Operating loss carryforwards, not subject to expiration	900.0
Tax credit carryforward, amount	33.5
State and Local Jurisdiction
Income Taxes
Operating loss carryforwards	1,100.0
Operating loss carryforwards, subject to expiration	237.0
Operating loss carryforwards, not subject to expiration	$ 651.0