Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Oct. 31, 2012	Oct. 31, 2011
OPERATING ACTIVITIES:
Net income	$ 41,453	$ 39,575
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	9,595	6,481
Gain on acquisition-related contingent liability settlement	(508)	0
Change in fair value of acquisition-related contingent consideration	706	(135)
Earnings of equity investee	72	21
Deferred income taxes	(1,067)	1,462
Share-based compensation expense	2,387	1,375
Change in operating assets and liabilities:
Accounts receivable	5,202	(10,625)
Inventories	4,735	(6,176)
Prepaid expense and other assets	42	(670)
Operating liabilities	(4,960)	6,562
Other operating activities, net	389	(141)
Net cash provided by operating activities	58,046	37,729
INVESTING ACTIVITIES:
Capital expenditures	(22,840)	(22,070)
Sales of short-term investments	0	1,000
Other investing activities, net	(125)	(595)
Net cash used in investing activities	(22,965)	(21,665)
FINANCING ACTIVITIES:
Dividends paid	(11,430)	(9,766)
Payments of acquisition-related contingent liability	(1,867)	0
Other financing activities, net	471	356
Net cash used in financing activities	(12,826)	(9,410)
Effect of exchange rate changes on cash	(10)	6
Net increase in cash and cash equivalents	22,245	6,660
Cash and cash equivalents at beginning of year	25,842	37,563
Cash and cash equivalents at end of year	$ 48,087	$ 44,223