Summary of Significant Accounting Policies Stock-Based Compensation (Details) (USD $)	12 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Service Based Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Black-Scholes Option Valuation Assumptions, Expected Term	5 years 11 months 18 days	5 years 11 months 5 days	5 years 10 months 21 days
Black-Scholes Option Valuation Assumptions, Expected Volatility Rate	37.32%	38.67%	39.41%
Black-Scholes Option Valuation Assumptions, Expected Dividend Yield	2.35%	2.21%	2.07%
Black-Scholes Option Valuation Assumptions, Risk-free Interest Rate	1.80%	0.91%	1.16%
Black-Scholes Option Valuation Assumptions, Weighted Average Market Value of Underlying Stock at Grant Date	$ 30.98	$ 30.58	$ 27.05
Black-Scholes Option Valuation Assumptions, Weighted-Average Exercise Price	$ 30.98	$ 30.58	$ 27.05
Black-Scholes Option Valuation Assumptions, Weighted Average Fair Value of Options Granted During Period	$ 9.17
Share-Based Compensation, Award Vesting Period	3 years
Share Based Compensation, Expiration Period of Options	10 years
Performance Based Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Black-Scholes Option Valuation Assumptions, Expected Term			6 years 6 months 26 days
Black-Scholes Option Valuation Assumptions, Expected Volatility Rate			39.21%
Black-Scholes Option Valuation Assumptions, Expected Dividend Yield			1.99%
Black-Scholes Option Valuation Assumptions, Risk-free Interest Rate			2.05%
Black-Scholes Option Valuation Assumptions, Weighted Average Market Value of Underlying Stock at Grant Date			$ 29.55
Black-Scholes Option Valuation Assumptions, Weighted-Average Exercise Price			$ 29.55
Black-Scholes Option Valuation Assumptions, Weighted Average Fair Value of Options Granted During Period			$ 10.01
Performance Based Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation, Expiration Period of Options	10 years