Discontinued operations (Details) (USD $)	3 Months Ended
	Apr. 30, 2014	Apr. 30, 2013
Discontinued operations
Net proceeds from sale of discontinued operations	$ 0	$ 16,123,000
Proceeds held in escrow	1,100,000
escrow released date	May 01, 2014
Disposal date HVAC subsidiary	Jun. 26, 2013
Net sales	176,000	10,503,000
(Loss) gain on disposal of discontinued operations	(12,000)	11,570,000
(Loss) income from discontinued operations	(67,000)	151,000
(Loss) income from discontinued operations before income taxes	(79,000)	11,721,000
Income tax expense	292,000	2,352,000
(Loss) income from discontinued operations, net of tax	$ (371,000)	$ 9,369,000