Intangible Assets - Schedule of intangible assets by major class (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 33,887	$ 33,887
Accumulated Amortization	28,726	26,282
Amortization expense	$ 2,400	4,000
Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life – Years	8 years 11 months 15 days
Customer contracts
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 26,518	26,518
Accumulated Amortization	$ 23,887	$ 21,719
Customer contracts | Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life – Years	8 years 1 month 28 days	8 years 1 month 28 days
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 4,673	$ 4,673
Accumulated Amortization	$ 2,143	$ 1,924
Trade names | Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life – Years	16 years 5 months 4 days	16 years 5 months 4 days
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,162	$ 1,162
Accumulated Amortization	$ 1,162	$ 1,162
Non-compete agreements | Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life – Years	2 years 6 months 10 days	2 years 6 months 10 days
Unpatented technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,534	$ 1,534
Accumulated Amortization	$ 1,534	$ 1,477
Unpatented technology | Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life – Years	5 years	5 years