Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2012	Jul. 31, 2011
Net sales:
Net sales	$ 886,569	$ 872,712	$ 1,705,739	$ 1,633,730
Earnings (losses) from operations:
Earnings from operations for segments	187,597	208,121	352,032	382,805
Americas [Member]
Net sales:
Net sales	433,989	438,223	819,663	812,875
Earnings (losses) from operations:
Earnings from operations for segments	83,866	94,683	139,807	169,096
Asia-Pacific [Member]
Net sales:
Net sales	174,138	173,241	369,208	340,488
Earnings (losses) from operations:
Earnings from operations for segments	35,026	46,706	86,086	95,340
Japan [Member]
Net sales:
Net sales	158,663	142,502	300,452	265,860
Earnings (losses) from operations:
Earnings from operations for segments	50,266	41,116	92,826	72,807
Europe [Member]
Net sales:
Net sales	100,214	101,349	188,121	186,975
Earnings (losses) from operations:
Earnings from operations for segments	20,597	24,182	37,252	43,950
Total reportable segments [Member]
Net sales:
Net sales	867,004	855,315	1,677,444	1,606,198
Earnings (losses) from operations:
Earnings from operations for segments	189,755	206,687	355,971	381,193
Other [Member]
Net sales:
Net sales	19,565	17,397	28,295	27,532
Earnings (losses) from operations:
Earnings from operations for segments	$ (2,158)	$ 1,434	$ (3,939)	$ 1,612