Debt - Additional Information (Detail) (USD $)	12 Months Ended			12 Months Ended						12 Months Ended		12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012 Other committed unsecured revolving credit facility [Member]	Jan. 31, 2013 Committed unsecured revolving credit facility [Member]	Jan. 31, 2013 Various other revolving credit facilities [Member]	Jan. 31, 2012 Various other revolving credit facilities [Member]	Jan. 31, 2013 2012 4.40% Series B Notes, due July 2042 [Member]	Jan. 31, 2012 2012 4.40% Series B Notes, due July 2042 [Member]	Jan. 31, 2013 2002 6.56% Series D, due July 2012 [Member]	Jan. 31, 2012 2002 6.56% Series D, due July 2012 [Member]	Jan. 31, 2013 Three-year revolving credit facility [Member]	Dec. 31, 2011 Three-year revolving credit facility [Member]	Jan. 31, 2013 Five-year revolving credit facility [Member]	Dec. 31, 2011 Five-year revolving credit facility [Member]
Debt Instrument [Line Items]
Previous credit facility											$ 200,000,000		$ 200,000,000
Total borrowing capacity	550,000,000			123,885,000	102,132,000
Amended credit facility										275,000,000		275,000,000
Spread on federal funds rate			0.50%
Line of credit facility remaining borrowing capacity										471,972,000		471,972,000
Weighted-average interest rate under credit facility		1.62%		3.74%	1.42%					2.04%		2.04%
Term of credit facility										3 years		5 years
Borrowing terms on debt										(i) local currency borrowing rates or (ii) the Federal Funds Rate plus 0.5%, whichever is higher, plus a margin based on the Company's leverage ratio.		(i) local currency borrowing rates or (ii) the Federal Funds Rate plus 0.5%, whichever is higher, plus a margin based on the Company's leverage ratio.
Revolving credit facilities outstanding				116,006,000	83,769,000
Percentage of interest rate on Senior Notes						4.40%	4.40%	6.56%	6.56%
Debt issued at par						250,000,000
Repayment of debt	60,000,000
Available letters of credit and financial guarantees	70,055,000
Letters of credit and financial guarantees, outstanding	30,454,000
Letters of credit and financial guarantees expires within one year	$ 58,620,000