Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	Oct. 25, 2014	Jul. 26, 2014
Loss Contingencies [Line Items]
Construction liens	$ 17.7
Credit Agreement, December 3, 2012, Maturing December 2017 | Revolving Credit Facility | Standby Letters of Credit
Loss Contingencies [Line Items]
Letters of credit outstanding amount	54.3	49.4
Performance Guarantee and Surety Bond
Loss Contingencies [Line Items]
Outstanding performance and other surety contract bonds	443.9	446.8
Other Accrued Liabilities
Loss Contingencies [Line Items]
Settlement liability	$ 0.6