8. Fair Value Measurements (Details) - Balance Sheet Grouping - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Accounts receivable unbilled, net - noncurrent	$ 19,387	$ 20,840
Accounts receivable trade, net - noncurrent	9,376	21,293
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt, including current maturities	258,672
Carrying Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Accounts receivable unbilled, net - noncurrent	19,387	20,840
Accounts receivable trade, net - noncurrent	9,376	21,293
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt, including current maturities	258,672	246,737
Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Accounts receivable unbilled, net - noncurrent	17,590	18,846
Accounts receivable trade, net - noncurrent	7,462	18,605
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt, including current maturities	$ 242,551	$ 243,865