Common Stock - Additional Information 2 (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Anti-dilutive securities excluded from earning per share computation	1,700,000	0	1,700,000	0
Warrant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Anti-dilutive securities excluded from earning per share computation	400,000	0	400,000	0
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Anti-dilutive securities excluded from earning per share computation	1,100,000	0	1,100,000	0
Restricted Stock Unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Anti-dilutive securities excluded from earning per share computation	200,000	0	200,000	0