Organization, Nature of Operations, and Principles of Consolidation - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2017 USD ($) Title Channel
Restructuring Cost And Reserve [Line Items]
Percentage of digital streaming exclusively available for subscribers	90.00%
Number of channels | Channel	3
Accounting Standards Update 2016-09 [Member]
Restructuring Cost And Reserve [Line Items]
Cumulative-effect adjustment | $	$ 0.2
Minimum [Member]
Restructuring Cost And Reserve [Line Items]
Number of titles available in digital content library | Title	8,000
Percentage of produced and owned content of total views	80.00%