Income Taxes - Deferred Taxes (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Mar. 31, 2019
Deferred tax assets:
Research tax credits	$ 6,521	$ 7,224
Net operating loss	84,694	38,194
Share-based compensation	8,573	6,106
Intangibles	52,922	38,673
Lease liability	2,633	0
Other	4,936	2,539
Subtotal	160,279	92,736
Valuation allowance	(157,525)	(92,330)
Deferred tax liabilities:
Depreciation	(409)	(406)
Right-of-use assets	(2,345)	0
Total deferred tax assets	$ 0	0
Accounting Standards Update 2016-16
Deferred tax assets:
Intangibles		38,700
Valuation allowance		$ (38,700)