Business Description and Summary of Significant Accounting Policies - Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Business Description and Summary of Significant Accounting Policies
Income tax expense	$ 325	$ 257	$ 473	$ 761
Income tax expense (% Change)			(37.80%)
Effective tax rate			21.50%	21.00%
Effective tax rate (% Change)			2.40%