Net Income (Loss) Per Share - Additional Information (Detail) - $ / shares		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 26, 2016	Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential Common Shares Upon Notes Conversion If Only Settled In Shares	[1]	8,201,000	8,931,000	8,696,000
Debt Instrument, Convertible, Conversion Price		$ 5.75				$ 5.75
Convertible Debt Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential Common Shares Upon Notes Conversion If Only Settled In Shares		22,304,348
Comcast Milestones Achievement [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 4.76			$ 4.76

[1] Excluded from the table above are the Notes, which are convertible under certain conditions into an aggregate of 22,304,348 shares of common stock. See Note 11, “Convertible Notes, Other Debts and Capital Leases,” for additional information on the Notes. Since the Company’s intent is to settle the principal amount of the Notes in cash, the treasury stock method is being used to calculate any potential dilutive effect of the conversion spread on diluted net income per share, if applicable. The conversion spread will have a dilutive impact on diluted net income per share when the Company’s average market price of its common stock for a given period exceeds the conversion price of $5.75 per share.