Goodwill and Intangible Assets - Intangible assets (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Intangible Assets
Gross Value	$ 236,378		$ 236,378
Accumulated Amortization	(53,787)		(46,965)
Intangible Assets, net	182,591		$ 189,413
Amortization expense	$ 6,822	$ 4,667
Trade name
Intangible Assets
Weighted Average Amortization Period	7 years 1 month 6 days		7 years 1 month 6 days
Gross Value	$ 11,255		$ 11,255
Accumulated Amortization	(4,211)		(3,845)
Intangible Assets, net	$ 7,044		$ 7,410
Client relationships
Intangible Assets
Weighted Average Amortization Period	12 years 2 months 12 days		12 years 2 months 12 days
Gross Value	$ 128,169		$ 128,169
Accumulated Amortization	(23,753)		(20,977)
Intangible Assets, net	$ 104,416		$ 107,192
Non-competition agreement
Intangible Assets
Weighted Average Amortization Period	5 years		5 years
Gross Value	$ 6,602		$ 6,602
Accumulated Amortization	(2,971)		(2,641)
Intangible Assets, net	$ 3,631		$ 3,961
Developed technology
Intangible Assets
Weighted Average Amortization Period	8 years		8 years
Gross Value	$ 68,593		$ 68,593
Accumulated Amortization	(18,134)		(15,870)
Intangible Assets, net	$ 50,459		$ 52,723
Patient database
Intangible Assets
Weighted Average Amortization Period	5 years		5 years
Gross Value	$ 21,700		$ 21,700
Accumulated Amortization	(4,702)		(3,617)
Intangible Assets, net	$ 16,998		$ 18,083
Domain name
Intangible Assets
Weighted Average Amortization Period	10 years		10 years
Gross Value	$ 59		$ 59
Accumulated Amortization	(16)		(15)
Intangible Assets, net	$ 43		$ 44