Net (Loss) Income Per Share - Additional Information (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Diluted computation increased	542,000	0	148,000	0
Share-based awards outstanding under equity plans	1,800,000	3,500,000	1,800,000	3,500,000
Option Plans [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Diluted computation increased	534,000		760,000