Short-term investments (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2024	Mar. 31, 2024
US Government Agency bonds
Short-term investments
Amortized cost	$ 171,822	$ 199,905
Gross unrealized gains	3	33
Gross unrealized losses	(118)	(117)
Credit Losses	0	0
Fair value	171,707	199,821
US Treasury bonds
Short-term investments
Amortized cost	145,854	146,417
Gross unrealized gains	1	11
Gross unrealized losses	(96)	(38)
Credit Losses	0	0
Fair value	145,759	146,390
Short-term investments
Short-term investments
Amortized cost	317,676	346,322
Gross unrealized gains	4	44
Gross unrealized losses	(214)	(155)
Credit Losses	0	0
Fair value	$ 317,466	$ 346,211