CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Apr. 30, 2013	Jan. 31, 2013
Current assets:
Accounts receivable, net of allowances	$ 2,505	$ 2,510
Stockholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock:
Treasury stock, at cost (in shares)	2,123,263	2,097,497
Common Class A [Member]
Common stock:
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	71,000,000	71,000,000
Common stock, shares issued (in shares)	14,148,905	14,148,217
Common Class B [Member]
Common stock:
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	4,000,000	4,000,000
Common stock, shares issued (in shares)	3,536,952	3,536,822