CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS (Unaudited) (USD $)	3 Months Ended		6 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Statement of Comprehensive Income [Abstract]
Net earnings	$ 124,120,000	$ 106,781,000	$ 249,729,000	$ 190,358,000
Other comprehensive earnings (loss), net of tax
Foreign currency translation adjustments	(4,955,000)	(15,346,000)	12,196,000	(30,784,000)
Unrealized (loss) gain on marketable securities	(513,000)	(920,000)	254,000	(105,000)
Unrealized loss on hedging instruments	(1,297,000)	(2,977,000)	(4,776,000)	(190,000)
Net unrealized gain on benefit plans	1,559,000	2,712,000	3,601,000	5,636,000
Other comprehensive loss, net of tax	(5,206,000)	(16,531,000)	11,275,000	(25,443,000)
Comprehensive earnings	$ 118,914,000	$ 90,250,000	$ 261,004,000	$ 164,915,000