Acquisitions - Mediture (Details) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 31, 2018 USD ($) D shares	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Goodwill		$ 90,919		$ 90,919		$ 74,613
Revenue		54,418	$ 32,731	146,960	$ 90,145
Net income		10,416	$ 6,165	$ (36,704)	$ 1,889
Trade name
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Weighted average amortization period				8 years 18 days		8 years 6 months 22 days
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 7 days		7 years 4 months 17 days
Non-competition agreement
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Weighted average amortization period				6 years 11 months 27 days		4 years 11 months 16 days
Mediture
Acquisition
Cash consideration	$ 18,500
Issuance of common stock (in shares) | shares	45,561
Worth of shares to be issued	$ 3,500
Number of trading days | D	15
Acquisition and integration costs		355		$ 367
Purchase price consideration
Cash consideration at closing, net of post-closing adjustments	$ 17,452
Stock consideration at closing	3,595
Total fair value of acquisition consideration	21,047
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Cash	2,427
Accounts receivable	898
Prepaid expenses and other current assets	136
Property and equipment	219
Goodwill	13,167
Total assets acquired	25,147
Accrued expenses and other liabilities	(3,811)
Trade accounts payable	(112)
Other long-term liabilities	(177)
Total purchase price, including contingent consideration	$ 21,047
Weighted average amortization period	9 years 6 months 15 days
Revenue		$ 1,114		$ 1,114
Type of Revenue [Extensible List]		Service [Member]		Service [Member]
Net income		$ 453		$ 453
Mediture | Trade name
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Intangible assets	$ 300
Weighted average amortization period	3 years
Mediture | Developed technology
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Intangible assets	$ 2,300
Weighted average amortization period	8 years 6 months
Mediture | Client relationships intangible asset
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Intangible assets	$ 4,400
Weighted average amortization period	11 years 10 months 24 days
Mediture | Non-competition agreement
Allocation of the purchase price based on the estimated fair values of the assets acquired and liabilities assumed
Intangible assets	$ 1,300
Weighted average amortization period	5 years