Acquisitions - Additional Information (Detail) - Pulpo Media Inc - USD ($) $ in Millions		12 Months Ended
	Jun. 18, 2014	Dec. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Ownership Interest acquired	100.00%
Business acquisition date		Jun. 18, 2014
Aggregate cash consideration	$ 15.0
Cash acquired	0.7
Fair value of contingent consideration	$ 1.4		$ 0.0	$ 0.1		$ 1.3
Additional consideration payment term		90 days
Contingent consideration agreement, payment period	3 years
Contingent consideration arrangements, maximum	$ 3.0
Contingent consideration arrangements, minimum	0.0
Contingent consideration, payment					$ 1.0
Accounts receivables assets acquired, fair value	1.6
Gross amount account receivables asset acquired	1.7
Amount due under contract expected to be uncollectible	$ 0.1