CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) (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, 2013	$ 2,611,318	$ 1,671,341	$ (93,875)	$ 1,269	$ 1,019,997	$ 12,586
Beginning Balance, Shares at Jan. 31, 2013	126,934			126,934
Exercise of stock options and vesting of restricted stock units ("RSUs")	18,687	0	0	11	18,676	0
Exercise of stock options and vesting of restricted stock units ("RSUs"), shares				1,114
Tax effect of exercise of stock options and vesting of RSUs	12,178	0	0	0	12,178	0
Share-based compensation expense	23,671	0	0	0	23,671	0
Cash dividends on Common Stock	(126,718)	(126,718)	0	0	0	0
Other comprehensive loss, net of tax	(2,302)	0	(2,302)	0	0	0
Net earnings	284,968	284,968	0	0	0	0
Non-controlling interests	152	0	0	0	0	152
Ending Balances at Oct. 31, 2013	$ 2,821,954	$ 1,829,591	$ (96,177)	$ 1,280	$ 1,074,522	$ 12,738
Ending Balance, Shares at Oct. 31, 2013	128,048			128,048