Common and Common Equivalent Shares - Schedule of Calculation of Shares Used in Basic and Diluted Net Income Per Share (Detail) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Weighted average number of common shares outstanding	92,360	92,269
Weighted average number of dilutive common share equivalents	783	822
Weighted average number of common and common equivalent shares outstanding	93,143	93,091
Antidilutive securities not included in the diluted net income per common share calculation	3	6