Basis of Presentation and Significant Accounting Policies - Allowance For Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Allowance for Doubtful Accounts
Allowance for doubtful accounts and billing adjustments [Roll Forward]
Beginning balance	$ 432	$ 553
Provision adjustment	227	180
ATRM beginning balance	223
Write-offs and recoveries, net	(234)	(301)
Ending balance	648	432
Reserves for Billing Adjustments
Allowance for doubtful accounts and billing adjustments [Roll Forward]
Beginning balance	18	9
Provision adjustment	248	219
ATRM beginning balance	0
Write-offs and recoveries, net	(246)	(210)
Ending balance	20	18
Reserves for Contractual Allowance
Allowance for doubtful accounts and billing adjustments [Roll Forward]
Beginning balance	0	447
Provision adjustment	0	19,221
ATRM beginning balance	0
Write-offs and recoveries, net	0	(19,668)
Ending balance	$ 0	$ 0