Income Taxes - TCJA and net operating loss carryforwards (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2020
Income Taxes [Line Items]
Increase (decrease) in deferred tax asset valuation allowance	$ 21.4
Domestic Tax Authority
Income Taxes [Line Items]
Income tax refund		$ 0.8
Cumulative net operating loss carryforwards	102.4
Tax credit carryforwards	38.7
State and Local Jurisdiction [Member]
Income Taxes [Line Items]
Cumulative net operating loss carryforwards	162.1
Tax credit carryforwards	20.4
Years Prior to 2018 | Domestic Tax Authority
Income Taxes [Line Items]
Cumulative net operating loss carryforwards	59.0
Years After 2018 | Domestic Tax Authority
Income Taxes [Line Items]
Cumulative net operating loss carryforwards	$ 43.4