Stockholder's Investments - Summary of Activity under Company's Share-Based Compensation Plans (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Beginning Balance, Price Lower Range	$ 19.96
Options Outstanding, Beginning Balance, Price Upper Range	54.05
Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Price	39.92
Options Exercised, Price Lower Range	19.96
Options Exercised, Price Upper Range	54.05
Options Cancelled, Price Lower Range	39.92
Options Cancelled, Price Upper Range	54.05
Options Outstanding, Ending Balance, Price Lower Range	19.96	$ 19.96
Options Outstanding, Ending Balance, Price Upper Range	$ 54.05	$ 54.05
Options, Outstanding [Roll Forward]
Shares Outstanding, Beginning Balance	1,273,382
Options Granted	303,052
Options Exercised	(77,272)
Options Cancelled	(25,094)
Shares Outstanding, Ending Balance	1,474,068	1,273,382
Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options Outstanding, Beginning Balance, Weighted Average Exercise Price	$ 37.84
Options Granted, Weighted Average Exercise Price	39.92	$ 54.05	$ 43.96
Options Exercised, Weighted Average Exercise Price	32.07
Options Cancelled, Weighted Average Exercise Price	44.82
Options Outstanding, Ending Balance, Weighted Average Exercise Price	$ 38.45	$ 37.84
Options Outstanding, Range of Exercise Prices [Abstract]
Exercise Price Range, Number of Outstanding Options	1,474,068
Exercise Price Range, Options Outstanding, Weighted Average Remaining Contractual Term	6 years 6 months
Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 38.45
Exercise Price Range, Number of Exercisable Options	949,668
Exercise Price Range, Exercisable Options, Weighted Average Remaining Contractual Term	5 years 4 months 24 days
Exercise Price Range, Exercisable Options, Weighted Average Exercise Price	$ 34.97
$19.96 - $26.99 [Member]
Options Outstanding, Range of Exercise Prices [Abstract]
Exercise Price Range, Number of Outstanding Options	217,913
Exercise Price Range, Options Outstanding, Weighted Average Remaining Contractual Term	3 years 9 months 18 days
Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 20.87
Exercise Price Range, Number of Exercisable Options	217,913
Exercise Price Range, Exercisable Options, Weighted Average Remaining Contractual Term	3 years 9 months 18 days
Exercise Price Range, Exercisable Options, Weighted Average Exercise Price	$ 20.87
$27.00 - $32.99 [Member]
Options Outstanding, Range of Exercise Prices [Abstract]
Exercise Price Range, Number of Outstanding Options	789,608
Exercise Price Range, Options Outstanding, Weighted Average Remaining Contractual Term	6 years 7 months 6 days
Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 37.05
Exercise Price Range, Number of Exercisable Options	501,997
Exercise Price Range, Exercisable Options, Weighted Average Remaining Contractual Term	5 years 2 months 12 days
Exercise Price Range, Exercisable Options, Weighted Average Exercise Price	$ 35.40
$33.00 - $43.98 [Member]
Options Outstanding, Range of Exercise Prices [Abstract]
Exercise Price Range, Number of Outstanding Options	466,547
Exercise Price Range, Options Outstanding, Weighted Average Remaining Contractual Term	7 years 8 months 12 days
Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 49.02
Exercise Price Range, Number of Exercisable Options	229,758
Exercise Price Range, Exercisable Options, Weighted Average Remaining Contractual Term	7 years 6 months
Exercise Price Range, Exercisable Options, Weighted Average Exercise Price	$ 47.39
Service Based Restricted Shares and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$ 6,167	$ 9,776
Restricted Shares and RSUs, Nonvested, Number of Shares [Roll Forward]
Restricted Shares and RSUs, Nonvested, Number	154,960
Restricted Shares and RSUs, Grants in Period	79,811
Restricted Shares and RSUs, Vested in Period	(69,436)
Restricted Shares and RSUs, Forfeited in Period	(8,869)
Restricted Shares and RSUs, Nonvested, Number	156,466	154,960
Restricted Shares and RSUs, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Restricted Shares and RSUs, Nonvested, Weighted Average Grant Date Fair Value	$ 47.39
Restricted Shares and RSUs, Grants in Period, Weighted Average Grant Date Fair Value	40.82	$ 53.38
Restricted Shares and RSUs, Vested in Period, Weighted Average Grant Date Fair Value	44.48
Restricted Shares and RSUs, Forfeitures, Weighted Average Grant Date Fair Value	46.14
Restricted Shares and RSUs, Nonvested, Weighted Average Grant Date Fair Value	$ 45.40	$ 47.39
Performance Based Restricted Shares and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested	$ 16,849	$ 14,013
Restricted Shares and RSUs, Nonvested, Number of Shares [Roll Forward]
Restricted Shares and RSUs, Nonvested, Number	126,060
Restricted Shares and RSUs, Grants in Period	64,634
Restricted Shares and RSUs, Vested in Period	(71,413)
Restricted Shares and RSUs, Nonvested, Number	119,281	126,060
Restricted Shares and RSUs, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Restricted Shares and RSUs, Nonvested, Weighted Average Grant Date Fair Value	$ 50.61
Restricted Shares and RSUs, Grants in Period, Weighted Average Grant Date Fair Value	60.73	$ 75.00	$ 50.70
Restricted Shares and RSUs, Vested in Period, Weighted Average Grant Date Fair Value	33.12
Restricted Shares and RSUs, Nonvested, Weighted Average Grant Date Fair Value	$ 61.05	$ 50.61