Earnings Per Common Share (Detail) - shares	3 Months Ended		6 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2021	Jan. 31, 2020
Earnings Per Share [Abstract]
Weighted-average common shares outstanding for basic earnings per share (in shares)	55,366,241	55,198,756	55,302,203	55,146,915
Unvested restricted stock units (in shares)	202,426	197,360	259,472	163,470
Weighted-average common shares outstanding assuming dilution (in shares)	55,568,667	55,396,116	55,561,675	55,310,385
Antidilutive stock options, unvested restricted stock units outstanding (in shares)	60,916	160,091	78,862	213,395