Income Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 31, 2011	Oct. 31, 2010
Income Taxes [Abstract]
Effective tax rate	25.50%	26.20%
Tax benefits due to favorable settlement of tax audits	$ 4.3	$ 2.7
Effective income tax rate continuing operations without consideration of discrete items	30.20%	29.90%
Unrecognized tax benefits	16.7
Accrued interest and penalties	1.4
Statute of limitations period, in years	5
Maximum reduction in amount of unrecognized tax benefits	3.0
Unrecognized tax benefits potential expiration date, months	12
Unrecognized tax benefits in dispute with various taxing authorities	$ 0.2