Income Taxes - net operating loss carryforwards (Details) - USD ($)	24 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
Noncurrent deferred tax asset, gross	$ 27,400,000	$ 30,800,000
Tax examination penalties and interest expense	0
Federal income tax reporting purposes
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	104,200,000
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	104,200,000
State and local income tax reporting purposes
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 90,800,000