Basis of presentation (Details) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) segment	Jun. 30, 2019 USD ($)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Number of operating segments \| segment			2
Number of reportable segments \| segment			2
Amortization of identifiable intangible assets	$ 210	$ 0	$ 420	$ 0
Cost of sales	36,612	35,916	80,297	71,074
Service
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of sales	9,912	$ 10,118	22,558	$ 20,385
Reclassification
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Amortization of identifiable intangible assets	(200)		(500)
Cost of sales	$ 200		$ 500

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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