Net Income Per Common Share - Summary of Weighted Average Number of Common Shares Outstanding (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Denominator:
Basic weighted average shares outstanding	46,063	45,651	45,956	45,486
Effect of dilutive stock options and restricted stock	1,257	1,400	1,306	1,476
Diluted weighted average shares outstanding	47,320	47,051	47,262	46,962