Goodwill and Intangible Assets - Intangible assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Intangible Assets
Gross Value	$ 236,378		$ 236,378		$ 236,378
Accumulated Amortization	(60,610)		(60,610)		(46,965)
Intangible Assets, net	175,768		175,768		$ 189,413
Amortization expense	6,823	$ 7,084	$ 13,645	$ 11,751
Trade name
Intangible Assets
Weighted Average Amortization Period			3 years 6 months		7 years 1 month 6 days
Gross Value	11,255		$ 11,255		$ 11,255
Accumulated Amortization	(4,577)		(4,577)		(3,845)
Intangible Assets, net	6,678		$ 6,678		$ 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		$ 128,169
Accumulated Amortization	(26,528)		(26,528)		(20,977)
Intangible Assets, net	101,641		$ 101,641		$ 107,192
Non-competition agreement
Intangible Assets
Weighted Average Amortization Period			5 years		5 years
Gross Value	6,602		$ 6,602		$ 6,602
Accumulated Amortization	(3,302)		(3,302)		(2,641)
Intangible Assets, net	3,300		$ 3,300		$ 3,961
Developed technology
Intangible Assets
Weighted Average Amortization Period			8 years		8 years
Gross Value	68,593		$ 68,593		$ 68,593
Accumulated Amortization	(20,398)		(20,398)		(15,870)
Intangible Assets, net	48,195		$ 48,195		$ 52,723
Patient database
Intangible Assets
Weighted Average Amortization Period			5 years		5 years
Gross Value	21,700		$ 21,700		$ 21,700
Accumulated Amortization	(5,787)		(5,787)		(3,617)
Intangible Assets, net	15,913		$ 15,913		$ 18,083
Domain name
Intangible Assets
Weighted Average Amortization Period			10 years		10 years
Gross Value	59		$ 59		$ 59
Accumulated Amortization	(18)		(18)		(15)
Intangible Assets, net	$ 41		$ 41		$ 44