Debt (Other Facilities) (Details) - USD ($)	Oct. 31, 2016	Jan. 31, 2016
Line of Credit Facility
Accounts Receivable, Net, Current	$ 2,866,028,000	$ 2,995,114,000
Line of Credit, Current	16,200,000
Standby Letters Of Credit	29,700,000
Line of Credit Facility, Current Borrowing Capacity	918,300,000
Revolving Credit Facility
Line of Credit Facility
Line of Credit Facility, Maximum Borrowing Capacity	500,000,000
Line Of Credit Facility Possible Future Increase To Maximum Borrowing Capacity	750,000,000
Credit Agreement, amount outstanding	0	0
Receivables securitization program
Line of Credit Facility
Line of Credit Facility, Maximum Borrowing Capacity	400,000,000
Accounts Receivable, Net, Current	764,200,000	721,100,000
Line of Credit, Amount Outstanding	0	0
Other committed and uncommitted revolving credit facilities
Line of Credit Facility
Line of Credit Facility, Maximum Borrowing Capacity	232,300,000
Line of Credit, Current	$ 16,200,000	$ 18,100,000
Line of Credit Facility, Interest Rate at Period End	7.50%	5.26%