Long-Term Debt Long-Term Debt (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2013	Jan. 31, 2012
Gross interest expense	$ 8,500,000	$ 8,500,000	$ 16,900,000	$ 16,900,000
Amortization of deferred financing costs	500,000	500,000	1,000,000	1,000,000
Interest costs incurred, capitalized	$ 0	$ 0	$ 0	$ 100,000