Retirement Benefit Plans (Defined Contribution Plans) (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Aug. 01, 2015
Aug. 02, 2014
Aug. 01, 2015
Aug. 02, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Defined contribution plan, total expense $ 14 $ 13 $ 27 $ 26