Other intangible assets (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	$ 25,496	$ 15,246
Amortization of intangible assets	9,000	2,400	$ 1,200
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	28,836	17,958
Intangible assets, less accumulated amortization	6,887	6,268
Intangible assets, net (excluding goodwill)	21,949	11,690
Noncompete agreements
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	3,941	3,439
Intangible assets, less accumulated amortization	2,309	1,957
Intangible assets, net (excluding goodwill)	1,632	1,482
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	12,927	8,094
Intangible assets, less accumulated amortization	11,012	6,020
Intangible assets, net (excluding goodwill)	$ 1,915	$ 2,074