Net Income (Loss) Per Share of Common Stock - Schedule of Computation of Basic and Diluted Net Income (Loss) Per Share of Common Stock (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
BASIC:
Net income (loss) attributable to common stockholders	$ (9,474)	$ (26,558)
Weighted-average common shares outstanding-basic	875,712	871,093
Basic net income (loss) per share	$ (0.01)	$ (0.03)
DILUTED:
Weighted-average common shares outstanding-basic	875,712	871,093
Weighted-average common shares outstanding-diluted	875,712	871,093
Diluted net income (loss) per share	$ (0.01)	$ (0.03)
Common Class A [Member]
BASIC:
Net income (loss) attributable to common stockholders	$ (8,356)	$ (22,471)
Weighted-average common shares outstanding-basic	772,364	737,061
Basic net income (loss) per share	$ (0.01)	$ (0.03)
DILUTED:
Net income (loss) attributable to common stockholders-basic	$ (8,356)	$ (22,471)
Net income (loss) attributable to common stockholders-diluted	$ (9,474)	$ (26,558)
Weighted-average common shares outstanding-basic	772,364	737,061
Weighted-average common shares outstanding-diluted	875,712	871,093
Diluted net income (loss) per share	$ (0.01)	$ (0.03)
Common Class B [Member]
BASIC:
Net income (loss) attributable to common stockholders	$ (896)	$ (3,461)
Weighted-average common shares outstanding-basic	82,831	113,515
Basic net income (loss) per share	$ (0.01)	$ (0.03)
DILUTED:
Net income (loss) attributable to common stockholders-basic	$ (896)	$ (3,461)
Net income (loss) attributable to common stockholders-diluted	$ (896)	$ (3,461)
Weighted-average common shares outstanding-basic	82,831	113,515
Weighted-average common shares outstanding-diluted	82,831	113,515
Diluted net income (loss) per share	$ (0.01)	$ (0.03)
Common Class C [Member]
BASIC:
Net income (loss) attributable to common stockholders	$ (222)	$ (626)
Weighted-average common shares outstanding-basic	20,517	20,517
Basic net income (loss) per share	$ (0.01)	$ (0.03)
DILUTED:
Net income (loss) attributable to common stockholders-basic	$ (222)	$ (626)
Net income (loss) attributable to common stockholders-diluted	$ (222)	$ (626)
Weighted-average common shares outstanding-basic	20,517	20,517
Weighted-average common shares outstanding-diluted	20,517	20,517
Diluted net income (loss) per share	$ (0.01)	$ (0.03)
Class C Convert To Class A [Member] | Common Class A [Member]
DILUTED:
Reallocation of net income (loss) as a result of common stock class conversion	$ (222)	$ (626)
Conversion of common stock class	20,517	20,517
Class B convert to Class A [Member] | Common Class A [Member]
DILUTED:
Reallocation of net income (loss) as a result of common stock class conversion	$ (896)	$ (3,461)
Conversion of common stock class	82,831	113,515