Acquisitions - Mediscan (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Payments of notes payable				$ 2,426	$ 2,426	$ 0
Mediscan
Business Acquisition [Line Items]
Recognition of earnout payment liability			$ 7,400
Payment for contingent liability			100
Mediscan | Earnout Notes Payable
Business Acquisition [Line Items]
Earnout performance criterion, conversion to note payable			$ 7,300
Payments of notes payable	$ 2,400	$ 2,400
Notes payable				$ 2,500
Stated interest rate (percent)				2.00%
Assumed Additional Contingent Purchase Price Liabilities | Mediscan
Business Acquisition [Line Items]
Contingent consideration, range of outcomes, high							$ 300	$ 300	$ 300
Payments for previous acquisition						$ 300