Net Income Per Common Share - Additional Information (Detail) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net Income Per Common Share:
Options to purchase common stock outstanding that would be considered anti-dilutive	1.1	2.0	1.1	2.0