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Property at Cost - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Apr. 29, 2017
Apr. 30, 2016
Jan. 28, 2017
Property, Plant and Equipment [Line Items]      
Depreciation expense $ 172.6 $ 160.0 $ 658.8
Reduction in accumulated depreciation and amortization   $ (840.0)