Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Oct. 31, 2011	Oct. 31, 2010
OPERATING ACTIVITIES:
Net income	$ 39,575	$ 33,131
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	6,481	5,578
Gain on disposition of assets	0	(451)
Change in fair value of acquisition-related contingent consideration	(135)	238
Deferred income taxes	1,462	(100)
Share-based compensation expense	1,375	788
Change in operating assets and liabilities:
Accounts receivable	(10,625)	(14,314)
Inventories	(6,176)	(2,638)
Prepaid expenses and other assets	(670)	(346)
Operating liabilities	6,562	4,533
Other operating activities, net	(120)	(131)
Net cash provided by operating activities	37,729	26,288
INVESTING ACTIVITIES:
Capital expenditures	(22,070)	(9,417)
Purchase of short-term investments	0	(1,700)
Sale of short-term investments	1,000	3,200
Proceeds from disposition of assets	0	888
Payments related to business acquisitions	(88)	(390)
Other investing activities, net	(507)	83
Net cash used in investing activities	(21,665)	(7,336)
FINANCING ACTIVITIES:
Dividends paid	(9,766)	(31,206)
Other financing activities, net	356	11
Net cash used in financing activities	(9,410)	(31,195)
Effect of exchange rate changes on cash	6	29
Net increase in cash and cash equivalents	6,660	(12,214)
Cash and cash equivalents:
Beginning of period	37,563	40,684
End of period	$ 44,223	$ 28,470