Debt (Other Facilities) (Narrative) (Details) - USD ($)	Jan. 31, 2016	Jan. 31, 2015
Line of Credit Facility [Line Items]
Accounts Receivable, Net, Current	$ 2,995,114,000	$ 2,811,963,000
Line of Credit, Amount Outstanding		0
Standby Letters Of Credit	29,600,000
Line of Credit Facility, Current Borrowing Capacity	845,900,000
Credit Agreement
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	500,000,000.0
Line Of Credit Facility Possible Future Increase To Maximum Borrowing Capacity	750,000,000.0
Receivables Securitization Program
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	400,000,000.0
Accounts Receivable, Net, Current	721,100,000	594,900,000
Line of Credit, Amount Outstanding	0
Other Committed And Uncommitted Revolving Credit Facilities
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	308,000,000
Line of Credit, Current	$ 18,100,000	$ 12,848,000
Line of Credit Facility, Interest Rate at Period End	5.26%	4.97%