Equity (Details) - USD ($) $ in Thousands		3 Months Ended
		Apr. 30, 2018	Apr. 30, 2017
Beginning Balance		$ 470,335	$ 473,993
Net income (loss)		8,115	(4,159)
Dividends		(4,604)	(2,982)
Adoption of new revenue recognition standard (Topic 606)		(724)
Stock repurchase		(1,186)	(1,028)
Stock options exercised		3,105	(692)
Supplemental executive retirement plan		32	32
Stock-based compensation expense		1,214	1,243
Net unrealized gain (loss) on investments, net of tax (benefit)		14	(12)
Net change in effective portion of hedging contracts, net of tax (benefit)		(127)	(145)
Foreign currency translation adjustments	[1]	(15,226)	(1,730)
Ending Balance		460,948	464,520
Common Stock Class Undefined
Beginning Balance	[2]	273	272
Stock options exercised	[2]	3	1
Ending Balance	[2]	276	273
Class A Common Stock
Beginning Balance	[3]	66	66
Stock options exercised	[3]		1
Ending Balance	[3]	66	67
Capital in Excess of Par Value
Beginning Balance		189,808	185,354
Stock options exercised		3,738	(1)
Supplemental executive retirement plan		32	32
Stock-based compensation expense		1,214	1,243
Ending Balance		194,792	186,628
Retained Earnings
Beginning Balance		388,739	415,919
Net income (loss)		8,115	(4,159)
Dividends		(4,604)	(2,982)
Adoption of new revenue recognition standard (Topic 606)		(724)
Ending Balance		391,526	408,778
Treasury Stock
Beginning Balance		(208,894)	(204,398)
Stock repurchase		(1,186)	(1,028)
Stock options exercised		(636)	(693)
Ending Balance		(210,716)	(206,119)
Accumulated Other Comprehensive Income
Beginning Balance		100,343	76,780
Net unrealized gain (loss) on investments, net of tax (benefit)		14	(12)
Net change in effective portion of hedging contracts, net of tax (benefit)		(127)	(145)
Foreign currency translation adjustments	[1]	(15,226)	(1,730)
Ending Balance		$ 85,004	$ 74,893

[1] The currency translation adjustment is not adjusted for income taxes to the extent that it relates to permanent investments of earnings in international subsidiaries.

[2] Each share of common stock is entitled to one vote per share on all matters submitted to a vote of the shareholders.

[3] Each share of class A common stock is entitled to 10 votes per share on all matters submitted to a vote of the shareholders. Each holder of class A common stock is entitled to convert, at any time, any and all of such shares into the same number of shares of common stock. Each share of class A common stock is converted automatically into common stock in the event that the beneficial or record ownership of such shares of class A common stock is transferred to any person, except to certain family members or affiliated persons deemed “permitted transferees” pursuant to the Company’s Restated Certificate of Incorporation as amended. The class A common stock is not publicly traded, and consequently, there is currently no established public trading market for these shares.