Restructuring Charges (Textuals) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended	36 Months Ended
	Jan. 27, 2017	Jan. 29, 2016	Oct. 30, 2015	Oct. 27, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 772	$ 26,659
Forecast
Restructuring Cost and Reserve [Line Items]
Restructuring expenses				$ 144,000
Restructuring cash costs				$ 90,000
Pension Plan
Restructuring Cost and Reserve [Line Items]
Contractual termination benefits	$ 0	9,600
Underground | Pension Plan
Restructuring Cost and Reserve [Line Items]
Contractual termination benefits		$ 9,600	$ 2,600