Fair value of financial assets and liabilities (Details) - USD ($)
$ in Thousands |
3 Months Ended |
9 Months Ended |
|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Mar. 31, 2019 |
| Fair value of financial assets and liabilities |
|
|
|
|
|
| Transfer from Leve 1 to Level 2, assets |
$ 0
|
$ 0
|
$ 0
|
$ 0
|
|
| Transfer from Leve 2 to Level 1, assets |
0
|
0
|
0
|
0
|
|
| Transfers into Level 3, assets |
0
|
0
|
0
|
0
|
|
| Transfer out of Level 3, assets |
0
|
0
|
0
|
0
|
|
| Transfer from Leve 1 to Level 2, liabilities |
0
|
0
|
0
|
0
|
|
| Transfer from Leve 2 to Level 1, liabilities |
0
|
0
|
0
|
0
|
|
| Transfers into Level 3, liabilities |
0
|
0
|
0
|
0
|
|
| Transfer out of Level 3, liabilities |
0
|
$ 0
|
0
|
$ 0
|
|
| Recurring |
|
|
|
|
|
| Fair value of financial assets and liabilities |
|
|
|
|
|
| Assets fair value |
163,852
|
|
163,852
|
|
$ 119,771
|
| Level 2 | Recurring |
|
|
|
|
|
| Fair value of financial assets and liabilities |
|
|
|
|
|
| Assets fair value |
163,852
|
|
163,852
|
|
119,771
|
| Money market funds | Recurring |
|
|
|
|
|
| Fair value of financial assets and liabilities |
|
|
|
|
|
| Assets fair value |
35,853
|
|
35,853
|
|
2,676
|
| Money market funds | Level 2 | Recurring |
|
|
|
|
|
| Fair value of financial assets and liabilities |
|
|
|
|
|
| Assets fair value |
35,853
|
|
35,853
|
|
2,676
|
| Commercial paper | Recurring |
|
|
|
|
|
| Fair value of financial assets and liabilities |
|
|
|
|
|
| Assets fair value |
42,172
|
|
42,172
|
|
46,687
|
| Commercial paper | Level 2 | Recurring |
|
|
|
|
|
| Fair value of financial assets and liabilities |
|
|
|
|
|
| Assets fair value |
42,172
|
|
42,172
|
|
46,687
|
| US Government Agency bonds | Recurring |
|
|
|
|
|
| Fair value of financial assets and liabilities |
|
|
|
|
|
| Assets fair value |
23,158
|
|
23,158
|
|
20,884
|
| US Government Agency bonds | Level 2 | Recurring |
|
|
|
|
|
| Fair value of financial assets and liabilities |
|
|
|
|
|
| Assets fair value |
23,158
|
|
23,158
|
|
20,884
|
| US Treasury bonds | Recurring |
|
|
|
|
|
| Fair value of financial assets and liabilities |
|
|
|
|
|
| Assets fair value |
28,105
|
|
28,105
|
|
41,057
|
| US Treasury bonds | Level 2 | Recurring |
|
|
|
|
|
| Fair value of financial assets and liabilities |
|
|
|
|
|
| Assets fair value |
28,105
|
|
28,105
|
|
41,057
|
| Corporate debt securities | Recurring |
|
|
|
|
|
| Fair value of financial assets and liabilities |
|
|
|
|
|
| Assets fair value |
34,564
|
|
34,564
|
|
8,467
|
| Corporate debt securities | Level 2 | Recurring |
|
|
|
|
|
| Fair value of financial assets and liabilities |
|
|
|
|
|
| Assets fair value |
$ 34,564
|
|
$ 34,564
|
|
$ 8,467
|