Repurchase of common stock - Narrative (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Mar. 31, 2020 |
May 08, 2019 |
|
| Equity [Abstract] | ||
| Amount authorized under share repurchase program | $ 25,000,000 | |
| Total shares repurchased (in shares) | 564,468 | |
| Stock repurchased during period | $ 7,904,000 | |
| Average price per share (in USD per share) | $ 14.03 | |
| Remaining authorized repurchase amount | $ 17,100,000 |