Net Income Per Common Share - Additional Information (Detail) - $ / shares			3 Months Ended		6 Months Ended
	Apr. 27, 2017	Feb. 17, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share [Abstract]
Cash dividend declared per common share (usd per share)	$ 0.10	$ 0.10	$ 0.10	$ 0.10	$ 0.20	$ 0.20