Acquisitions - SinfoniaRx (Details) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 06, 2017 USD ($) D $ / shares shares	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Goodwill		$ 63,125		$ 63,125		$ 21,686
Service revenue		8,647	$ 3,443	19,222	$ 8,017
Net income (loss)		7,695	$ (142)	$ 3,350	$ (219)
Trade names
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Weighted average amortization period				8 years 5 months 23 days		5 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				7 years 10 months 13 days		7 years 9 months 4 days
Non-competition agreement intangible asset
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Weighted average amortization period				4 years 11 months 12 days		4 years 7 months 21 days
SinfoniaRx
Acquisition
Cash consideration	$ 35,000
Percentage of contingent consideration payable in cash	50.00%
Percentage of contingent consideration payable in stock	50.00%
Aggregate value of contingent consideration	$ 130,000
Issuance of common stock (in shares) | shares	520,821
Issuance price (in dollars per share) | $ / shares	$ 19.20
Number of trading days | D	20
Direct acquisition costs	$ 949
Purchase price consideration
Cash consideration at closing, net of post-closing adjustments	34,670
Stock consideration at closing	11,541
Estimated fair value of contingent consideration	26,406
Total fair value of acquisition consideration	72,617
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Cash	218
Accounts receivable	8,309
Prepaid and other current assets	1,001
Property and equipment	1,419
Other assets	94
Goodwill	41,439
Total assets acquired	93,625
Accrued expenses and other liabilities	(2,667)
Trade accounts payable	(8,769)
Debt assumed	(675)
Deferred income tax liability	(8,897)
Total purchase price, including contingent consideration of $26,406	72,617
Contingent consideration	$ 26,406
Weighted average amortization period	7 years 8 months 5 days
Service revenue		2,638		$ 2,638
Net income (loss)		$ 285		$ 285
SinfoniaRx | Maximum
Acquisition
Cash consideration	$ 35,000
SinfoniaRx | Trade names
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Intangible assets	$ 4,429
Weighted average amortization period	10 years
SinfoniaRx | Developed technology
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Intangible assets	$ 12,640
Weighted average amortization period	8 years
SinfoniaRx | Client relationships intangible asset
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Intangible assets	$ 19,579
Weighted average amortization period	7 years 6 months 22 days
SinfoniaRx | Non-competition agreement intangible asset
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Intangible assets	$ 4,497
Weighted average amortization period	5 years