Other Data - State Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
State income tax expense
Texas gross margins tax	$ 564	$ 546	$ 550
Other	8	8	6
Total state income tax expense	572	554	556
State income tax payments, net of refunds and collections	$ 560	$ 557	$ 549