Discontinued operations (Details) (USD $)	3 Months Ended
	Apr. 30, 2013	Apr. 30, 2012
Discontinued operations
Net proceeds from sale of discontinued operations	$ 14,998,000	$ 0
Proceeds held in escrow	1,100,000
escrow released date	May 01, 2014
Sales included in discontinued operations	7,449,000	8,229,000
Gain on disposal of discontinued operations	11,401,000	0
Income from discontinued operations	74,000	578,000
Income from discontinued operations before income taxes	11,475,000	578,000
Income tax expense from discontinued operations	2,356,000	37,000
Income from discontinued operations, net of tax	$ 9,119,000	$ 541,000