Summary of Significant Accounting Policies Allowance for credit losses (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020 USD ($)
Unbilled Revenue
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 397
Provision for credit loss expense	727
Write-offs	(511)
Recoveries	112
Total ending allowance balance	725
Customer Receivables
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	374
Provision for credit loss expense	875
Write-offs	(509)
Recoveries	135
Total ending allowance balance	$ 875