CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands	Total	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Non-controlling Interests [Member]
Beginning Balances at Jan. 31, 2010	$ 1,883,239	$ 1,151,109	$ (33,265)	$ 1,263	$ 764,132
Beginning Balance, Shares at Jan. 31, 2010				126,326
Exercise of stock options and vesting of restricted stock units ("RSUs")	65,683			23	65,660
Exercise of stock options and vesting of restricted stock units ("RSUs"), shares				2,382
Tax effect of exercise of stock options and vesting of RSUs	9,811				9,811
Share-based compensation expense	25,815				25,815
Issuance of Common Stock under Employee Profit Sharing and Retirement Savings ("EPSRS") Plan	5,000			1	4,999
Issuance of Common Stock under the Employee Profit Sharing and Retirement Savings Plan ("EPSRS"), shares				104
Purchase and retirement of Common Stock	(80,786)	(74,318)		(18)	(6,450)
Purchase and retirement of Common Stock, shares	(1,843)			(1,843)
Cash dividends on Common Stock	(120,390)	(120,390)
Other comprehensive (loss) earnings, net of tax	20,700		20,700
Net earnings	368,403	368,403
Ending Balances at Jan. 31, 2011	2,177,475	1,324,804	(12,565)	1,269	863,967
Ending Balance, Shares at Jan. 31, 2011				126,969
Exercise of stock options and vesting of restricted stock units ("RSUs")	65,566			23	65,543
Exercise of stock options and vesting of restricted stock units ("RSUs"), shares				2,272
Tax effect of exercise of stock options and vesting of RSUs	20,944				20,944
Share-based compensation expense	30,753				30,753
Issuance of Common Stock under Employee Profit Sharing and Retirement Savings ("EPSRS") Plan	4,500			1	4,499
Issuance of Common Stock under the Employee Profit Sharing and Retirement Savings Plan ("EPSRS"), shares				64
Purchase and retirement of Common Stock	(174,118)	(158,601)		(26)	(15,491)
Purchase and retirement of Common Stock, shares	(2,629)			(2,629)
Cash dividends on Common Stock	(142,840)	(142,840)
Other comprehensive (loss) earnings, net of tax	(72,565)		(72,565)
Net earnings	439,190	439,190
Ending Balances at Jan. 31, 2012	2,348,905	1,462,553	(85,130)	1,267	970,215
Ending Balance, Shares at Jan. 31, 2012	126,676			126,676
Exercise of stock options and vesting of restricted stock units ("RSUs")	13,012			10	13,002
Exercise of stock options and vesting of restricted stock units ("RSUs"), shares				1,026
Tax effect of exercise of stock options and vesting of RSUs	11,730				11,730
Share-based compensation expense	27,224				27,224
Issuance of Common Stock under Employee Profit Sharing and Retirement Savings ("EPSRS") Plan	3,150			45	3,150
Purchase and retirement of Common Stock	(54,107)	(48,775)		(8)	(5,324)
Purchase and retirement of Common Stock, shares	(813)			(813)
Cash dividends on Common Stock	(158,594)	(158,594)
Other comprehensive (loss) earnings, net of tax	(8,745)		(8,745)
Net earnings	416,157	416,157
Non-controlling interests	12,586					12,586
Ending Balances at Jan. 31, 2013	$ 2,611,318	$ 1,671,341	$ (93,875)	$ 1,269	$ 1,019,997	$ 12,586
Ending Balance, Shares at Jan. 31, 2013	126,934			126,934