Segment Information - Company's Segments Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Net sales:
Net sales	$ 992,930,000	$ 925,884,000	$ 2,005,062,000	$ 1,821,368,000
Earnings from operations:
Earnings from operations	241,983,000	206,998,000	486,040,000	389,960,000
Americas [Member]
Net sales:
Net sales	483,595,000	443,856,000	922,283,000	851,553,000
Earnings from operations:
Earnings from operations	109,805,000	87,731,000	191,289,000	146,693,000
Asia-Pacific [Member]
Net sales:
Net sales	236,805,000	208,325,000	497,749,000	431,752,000
Earnings from operations:
Earnings from operations	65,492,000	49,882,000	137,333,000	105,341,000
Japan [Member]
Net sales:
Net sales	119,085,000	136,395,000	292,979,000	280,922,000
Earnings from operations:
Earnings from operations	39,173,000	48,235,000	110,669,000	101,654,000
Europe [Member]
Net sales:
Net sales	120,033,000	111,247,000	221,318,000	204,233,000
Earnings from operations:
Earnings from operations	25,114,000	22,338,000	42,086,000	36,616,000
Reportable Geographical Components [Member]
Net sales:
Net sales	959,518,000	899,823,000	1,934,329,000	1,768,460,000
Earnings from operations:
Earnings from operations	239,584,000	208,186,000	481,377,000	390,304,000
Other [Member]
Net sales:
Net sales	33,412,000	26,061,000	70,733,000	52,908,000
Earnings from operations:
Earnings from operations	$ 2,399,000	$ (1,188,000)	$ 4,663,000	$ (344,000)