Income Taxes - Deferred Tax Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Taxes
Changes in estimated realization of deferred tax assets	$ (300)	$ (300)
Balance at beginning of period	5,694	6,022	$ 6,393
Charges to costs and expenses	22	61	456
Deductions	296	389	827
Balance at end of period	$ 5,420	$ 5,694	$ 6,022