Stock-Based Compensation - Summary of Stock Option Activity under Company's Share-Based Compensation Plans (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended				9 Months Ended		9 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2014 Service Based Option [Member]	Jul. 31, 2013 Service Based Option [Member]	Apr. 30, 2014 Service Based Restricted Shares and Restricted Stock Units [Member]	Jul. 31, 2013 Service Based Restricted Shares and Restricted Stock Units [Member]	Apr. 30, 2014 Performance Based Restricted Shares and Restricted Stock Units [Member]	Jul. 31, 2013 Performance Based Restricted Shares and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding, ending balance, weighted average remaining contractual term	5 years 8 months 12 days
Options outstanding, exercisable, weighted average remaining contractual term	4 years 8 months 12 days
Options outstanding, ending balance, aggregate intrinsic value	$ 1,253
Options outstanding, exercisable, aggregate intrinsic value	$ 1,253
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Options Outstanding			4,375,545	5,106,585
Options Outstanding, Weighted Average Exercise Price			$ 30.70	$ 30.68
Options, Grants in Period			375,272
Options, Grants in Period, Weighted Average Exercise Price	$ 30.98	$ 30.54	$ 30.98
Options, Exercised in Period			(407,507)
Options, Exercises in Period, Weighted Average Exercise Price			$ 26.99
Options, Forfeitures or Expirations in Period			(698,805)
Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price			$ 32.90
Options Exercisable	3,131,418	3,736,320
Weighted average exercise price of options exercisable	$ 30.97	$ 30.70
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity Instruments Other than Options, Nonvested, Number					109,173	5,000	80,000	231,667
Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value					$ 31.02	$ 32.99	$ 32.50	$ 31.43
Equity Instruments Other than Options, Grants in Period					108,055		0
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value					$ 30.93		$ 0.00
Equity Instruments Other than Options, Vested in Period					0		(35,001)
Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value					$ 0.00		$ 28.35
Equity Instruments Other than Options, Forfeited in Period					(3,882)		(116,666)
Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value					$ 31.03		$ 31.61