Income taxes Components of income tax expense (benefit) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012
Components of income tax expense (benefit) [Abstract]
Current Federal Tax Expense (Benefit)	$ (1,255)	$ 183
Current Foreign Tax Expense (Benefit)	229	627
State and Other	(33)	253
Current Income Tax Expense (Benefit)	(1,059)	1,063
Deferred Federal Income Tax Expense (Benefit)	11,816	(880)
Deferred Foreign Income Tax Expense (Benefit)	413	(273)
State and other	(380)	107
Deferred tax expense (benefit)	11,849	(989)
Increase (Decrease) in Deferred Income Taxes		(1,046)
Income Tax Expense (Benefit)	$ 10,790	$ 17