Stock-Based Compensation - Summary of Stock Option Activity under Company's Share-Based Compensation Plans (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Oct. 31, 2015	Oct. 31, 2014
Stock Option Activity
Options Outstanding at July 31, 2015	3,500,951
Options Outstanding at July 31, 2015, Weighted Average Exercise Price	$ 29.64
Options, Grants in Period	871,993
Options, Grants in Period, Weighted Average Exercise Price	$ 19.97	$ 22.66
Options, Exercised in Period	0
Options, Exercises in Period, Weighted Average Exercise Price	$ 0
Options, Forfeitures or Expirations in Period	(152,462)
Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 29.50
Options Outstanding at October 31, 2015	4,220,482
Options Outstanding at October 31, 2015, Weighted Average Exercise Price	$ 27.64
Options Outstanding, Weighted Average Remaining Contractual Term	6 years
Options Outstanding, Aggregate Intrinsic Value	$ 2,953
Options Exercisable, Weighted Average Exercise Price	$ 30.32	$ 30.94
Options Exercisable	2,923,276	3,339,992
Options Exercisable, Weighted Average Remaining Contractual Term	4 years 6 months
Options Exercisable, Aggregate Intrinsic Value	$ 390
Service-Based RSU Activity
Service-Based RSUs Outstanding at July 31, 2015	677,454
Service-Based RSUs, Outstanding at July 31, 2015, Weighted Average Grant Date Fair Value	$ 24.72
Service-Based RSUs, Grants in Period	168,566
Service-Based RSUs, Grants in Period, Weighted Average Grant Date Fair Value	$ 19.98	$ 23.45
Service-Based RSUs, Vested in Period	(69,829)
Service-Based RSUs, Vested in Period, Weighted Average Grant Date Fair Value	$ 25.00
Service-Based RSUs, Forfeited in Period	(28,194)
Service-Based RSUs, Forfeitures, Weighted Average Grant Date Fair Value	$ 24.00
Service-Based RSUs Outstanding at October 31, 2015	747,997
Service-Based RSUs, Outstanding at October 31, 2015, Weighted Average Grant Date Fair Value	$ 23.66