Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended						12 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Significant Accounting Policies [Line Items]
Restructuring costs	$ 800	$ 1,200	$ 900	$ 2,300	$ 2,300	$ 600	$ 2,630	$ 6,052	$ 3,571
Sales allowance, billing-related adjustments			600				800	600
Prepaid implementation costs			400				500	400
Capitalized implementation costs			3,187				4,840	3,187
Implementation costs, amortization							400	0	0
Outstanding standby letters of credit as collateral			17,000				16,700	17,000
Unbilled contracts receivable			48,300				140,000	48,300
Equity compensation							6,900	5,400	3,400
Advertising costs							9,500	6,200	7,900
Cumulative impact of currency fluctuations			1,300				1,300	1,300
Claims-Based Liability Insurance
Significant Accounting Policies [Line Items]
Self insured retention per claim							500
Claims-Based Liability Insurance | MDA Holdings Inc
Significant Accounting Policies [Line Items]
Letter of credit for malpractice claims			$ 1,500				1,500	1,500
Lease-Related Exit Costs
Significant Accounting Policies [Line Items]
Restructuring costs							$ 544	$ 2,190	$ 1,311
Revenue Benchmark | Service | Services
Significant Accounting Policies [Line Items]
Concentration risk percentage							5.00%	5.00%	5.00%
Minimum
Significant Accounting Policies [Line Items]
Threshold period, past due for payment of services provided							30 days
Estimated useful life of assets							3 years
Short term leases period							3 months
Intangible assets- useful life							5 years
Maximum
Significant Accounting Policies [Line Items]
Threshold period, past due for payment of services provided							60 days
Estimated useful life of assets							10 years
Short term leases period							6 months
Intangible assets- useful life							16 years