Long-Term Debt Long-Term Debt (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2013	Apr. 30, 2012
Gross interest expense	$ 8,400,000	$ 8,400,000	$ 25,300,000	$ 25,400,000
Amortization of deferred financing costs	500,000	500,000	1,500,000	1,500,000
Interest costs incurred, capitalized	$ 0	$ 0	$ 0	$ 100,000