Income taxes Components of income tax expense (benefit) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013
Components of income tax expense (benefit) [Abstract]
Current federal tax benefit	$ (245)	$ (964)
Current foreign tax expense	3,024	229
State and other	(82)	(34)
Current income tax expense (benefit)	2,697	(769)
Deferred federal income tax (benefit) expense	(2,715)	12,545
Deferred foreign income tax (benefit) expense	(475)	466
State and other	0	(417)
Deferred tax (benefit) expense	(3,190)	12,594
Income tax (benefit) expense	$ (493)	$ 11,825