CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS (USD $)	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Statement of Comprehensive Income [Abstract]
Net earnings	$ 484,179,000	$ 181,369,000	$ 416,157,000
Other comprehensive (loss) earnings, net of tax
Foreign currency translation adjustments	(93,130,000)	(27,218,000)	(5,145,000)
Unrealized (loss) gain on marketable securities	(765,000)	828,000	1,719,000
Unrealized gain (loss) on hedging instruments	1,208,000	(3,400,000)	5,522,000
Net unrealized (loss) gain on benefit plans	(139,227,000)	65,117,000	(10,841,000)
Other comprehensive (loss) earnings, net of tax	(231,914,000)	35,327,000	(8,745,000)
Comprehensive earnings	$ 252,265,000	$ 216,696,000	$ 407,412,000