Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Valuation Allowance [Abstract]
Charges to expense	$ 855	$ 428	$ 393
Uncollected balances written off, net of recoveries	(677)	(774)	(855)
Balance, end of year	1,065	464	810
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance, beginning of year	464	810	1,272
Accounts Receivable, Allowance for Credit Loss	1,065	810	$ 1,272
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Valuation Allowance [Abstract]
Balance, end of year		887
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance, beginning of year	887
Accounts Receivable, Allowance for Credit Loss	$ 887	$ 887