Long-Term Debt Long-Term Debt (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Jul. 31, 2015	May. 01, 2015
Gross interest expense	$ 10,600	$ 13,600
Long-term Debt	830,377	820,260	$ 816,830
Amortization of deferred financing costs	200	400
Interest costs incurred, capitalized		0
Industrial Development Bonds [Member]
Long-term Debt	$ 0	$ 215,000	$ 0	$ 0