Condensed Consolidated Statements of Stockholders' Equity and Comprehensive Earnings (Unaudited) (USD $) In Thousands, unless otherwise specified	Total	Retained Earnings	Accumulated Other Comprehensive (Loss) Gain	Common Stock	Additional Paid-in Capital
Beginning Balance at Jan. 31, 2011	$ 2,177,475	$ 1,324,804	$ (12,565)	$ 1,269	$ 863,967
Beginning Balance, Shares at Jan. 31, 2011	126,969			126,969
Exercise of stock options and vesting of restricted stock units ("RSUs")	62,644			21	62,623
Exercise of stock options and vesting of restricted stock units ("RSUs"), shares				2,098
Tax effect of exercise of stock options and vesting of RSUs	15,820				15,820
Share-based compensation expense	23,117				23,117
Issuance of Common Stock under the Employee Profit Sharing and Retirement Savings Plan	4,500			1	4,499
Issuance of Common Stock under the Employee Profit Sharing and Retirement Savings Plan, Shares				64
Purchase and retirement of Common Stock	(138,813)	(126,681)		(21)	(12,111)
Purchase and retirement of Common Stock, shares				(2,104)
Cash dividends on Common Stock	(106,066)	(106,066)
Deferred hedging loss, net of tax	(10,789)		(10,789)
Unrealized loss on marketable securities, net of tax	(420)		(420)
Foreign currency translation adjustments, net of tax	21,914		21,914
Net unrealized gain on benefit plans, net of tax	2,546		2,546
Net earnings	260,795	260,795
Other comprehensive gain (loss), net of tax:
Deferred hedging loss	(10,789)		(10,789)
Foreign currency translation adjustments	21,914		21,914
Unrealized (loss) gain on marketable securities	(420)		(420)
Net unrealized gain on benefit plans	2,546		2,546
Comprehensive earnings	274,046
Ending Balance at Oct. 31, 2011	$ 2,312,723	$ 1,352,852	$ 686	$ 1,270	$ 957,915
Ending Balance, Shares at Oct. 31, 2011	127,027			127,027