Income Taxes - Deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 30, 2019
Deferred tax assets related to:
U.S. and foreign net operating loss carryforwards	$ 14,388	$ 16,017
Accrued compensation	1,222	1,262
Unrealized gain/loss on investments	1,751	1,828
Partnership investment	0	237
U.S. credit carryforwards	751	1,225
Stock compensation	919	190
Acquisition costs	62	75
Other	85	76
Deferred tax assets	19,178	20,910
Valuation allowance	(11,697)	(20,435)
Total deferred tax assets	7,481	475
Deferred tax liabilities related to:
Partnership investment	151	0
Bond interest accretion	698	0
Deferred tax liabilities	849	0
Total deferred tax assets	849	0
Deferred income taxes (net)	$ 6,632	$ 475