Shareholders' Equity (Company's Common Share Repurchase And Issuance Activity) (Details) - $ / shares	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015
Increase (Decrease) in Treasury Stock [Roll Forward]
Treasury stock, beginning balance, Shares	21,866,069	21,177,130
Shares of common stock repurchased under share repurchase programs, Shares	2,497,029	896,718
Treasury stock, ending balance, Shares	24,163,402	21,866,069
Treasury stock, beginning balance, Weighted-average price per share	$ 42.95	$ 42.26
Shares of common stock repurchased under share repurchase programs, Weighted-average price per share	58.87	59.10
Treasury stock, ending balance, Weighted-average price per share	$ 44.59	$ 42.95
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures	199,696	207,779