Acquisitions - Additional Information (Details) - Crisp Media, Inc $ / shares in Units, $ in Millions	May 31, 2017 USD ($) $ / shares shares
Business Acquisition [Line Items]
Total preliminary acquisition consideration	$ 51.9
Cash payments for purchase of assets	$ 24.1
Number of shares Issuable | shares	1,177,927
Total acquisition consideration (Values)	$ 13.0
Business acquisitions, fair value of common stock per share | $ / shares	$ 11.00
Contingent consideration payable in cash	$ 24.5
Contingent consideration, fair value	$ 14.8
Contingent consideration, milestones achievement period	1 year
Contingent consideration payout period	105 days
Business combination, contingent consideration payable start date	May 31, 2018