Shareholders' Equity (Company's Common Share Repurchase And Issuance Activity) (Details) (USD $)	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012
Increase (Decrease) in Treasury Stock [Roll Forward]
Treasury stock, beginning balance, Shares	18,166,761	12,517,538
Treasury stock, beginning balance, Weighted-average price per share	$ 40.71	$ 37.28
Shares of common stock repurchased under share repurchase programs, Shares	3,878,548	6,736,436
Shares of common stock repurchased under share repurchase programs, Weighted-average price per share	$ 49.33	$ 46.74
Shares of treasury stock reissued	(608,743)	(1,087,213)
Treasury stock, ending balance, Shares	21,436,566	18,166,761
Treasury stock, ending balance, Weighted-average price per share	$ 42.26	$ 40.71