Derivatives and Hedging Activities (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 31, 2011	Oct. 31, 2010
Pre-tax effects of derivative instruments as cash flow hedges
Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion)	$ (11,508)	$ (6,720)
Net Investment Hedging [Member]
Pre-tax effects of derivative instruments as cash flow hedges
Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion)	(298)	0
Amount of Gain or (Loss) Reclassified From Accumulated OCI Into Income (Effective Portion)	0	0
Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion)	0	0
Net Investment Hedging [Member] | Foreign Exchange Contract [Member] | Investment and other income - net [Member]
Pre-tax effects of derivative instruments as cash flow hedges
Amount of Gain or (Loss) Reclassified From Accumulated OCI Into Income (Effective Portion)	0	0
Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion)	0	0
Net Investment Hedging [Member] | Foreign Currency Denominated Debt [Member]
Pre-tax effects of derivative instruments as cash flow hedges
Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion)	(11,210)	(6,720)
Net Investment Hedging [Member] | Foreign Currency Denominated Debt [Member] | Investment and other income - net [Member]
Pre-tax effects of derivative instruments as cash flow hedges
Amount of Gain or (Loss) Reclassified From Accumulated OCI Into Income (Effective Portion)	0	0
Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion)	$ 0	$ 0