|
Commitment and contingencies (Details) (USD $)
|
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
|
Oct. 31, 2014
|
Oct. 31, 2013
|
Oct. 31, 2014
|
Oct. 31, 2013
|
Mar. 31, 2014
|
|
| Commitments and Contingencies Disclosure [Abstract] | |||||
| Office lease, additional commitment | $ 1,100,000 | ||||
| Lease expense for office space | 374,000 | 237,000 | 944,000 | 672,000 | |
| Expenses for other agreements | $ 67,000 | $ 62,000 | $ 166,000 | $ 127,000 | |