Acquisitions - Prescribe Wellness (Details) $ in Thousands		3 Months Ended						9 Months Ended		12 Months Ended
	Mar. 05, 2019 USD ($) company	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Goodwill		$ 150,790						$ 150,790		$ 108,213
Revenue		74,270			$ 54,418			211,484	$ 146,960
Net income (loss)		(8,104)	$ (6,529)	$ (10,979)	10,416	$ (29,026)	$ (18,094)	(25,612)	(36,704)
Amortization expense		6,927			$ 2,782			$ 18,678	$ 7,949
Trade name
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Weighted average amortization period								7 years		8 years
Developed technology
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Weighted average amortization period								8 years		7 years 2 months 12 days
Patient database
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Weighted average amortization period								5 years
Prescribe Wellness
Acquisition
Cash consideration	$ 150,000
Direct acquisition costs		11						$ 3,241
Purchase price consideration
Cash consideration at closing, net of post-closing adjustments	148,626
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Accounts receivable	2,608
Prepaid expenses and other current assets	1,345
Property and equipment	1,155
Operating lease right-of-use-assets	1,467
Goodwill	30,714
Total assets acquired	157,189
Operating lease liabilities	(1,467)
Trade accounts payable	(1,633)
Accrued expenses and other liabilities	(5,463)
Total purchase price	$ 148,626
Weighted average amortization period	11 years 4 months 24 days
Revenue		$ 8,271						$ 18,381
Revenue from Contract with Customer, Product and Service		us-gaap:ServiceMember						us-gaap:ServiceMember
Reduction to revenue recorded due to purchase accounting effects of recording deferred revenue at fair value		$ (463)						$ (1,210)
Net income (loss)		(3,033)						(6,829)
Amortization expense		$ 3,113						$ 7,264
Prescribe Wellness | Minimum
Acquisition
Number of pharmacies with which acquiree facilitates collaboration | company	10,000
Prescribe Wellness | Trade name
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Intangible assets	$ 4,100
Weighted average amortization period	5 years
Prescribe Wellness | Developed technology
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Intangible assets	$ 20,000
Weighted average amortization period	10 years
Prescribe Wellness | Patient database
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Intangible assets	$ 21,700
Weighted average amortization period	5 years
Prescribe Wellness | Client relationships intangible asset
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Intangible assets	$ 74,100
Weighted average amortization period	14 years