Goodwill and Intangible Assets - Additional Information (Details) (USD $)	3 Months Ended	12 Months Ended			3 Months Ended
	Oct. 25, 2013	Oct. 25, 2013	Oct. 26, 2012	Oct. 28, 2011	Oct. 25, 2013 Underground Mining Machinery	Oct. 25, 2013 Surface Mining Equipment	Jan. 25, 2013 International Mining Machinery Holdings Ltd. Customer relationships	Jan. 25, 2013 International Mining Machinery Holdings Ltd. Backlog	Jan. 25, 2013 International Mining Machinery Holdings Ltd. Trademarks
Goodwill [Line Items]
Decrease in Intangible Assets							$ 81,200,000	$ 3,800,000	$ 3,700,000
Intangible asset impairment charges	155,200,000	155,200,000	0	0	130,200,000	25,000,000
Amortization expense for finite-lived intangible assets		$ 13,600,000	$ 37,400,000	$ 12,600,000