CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Statement of Income and Comprehensive Income [Abstract]
Net income (loss)	$ (3,824)	$ (4,620)	$ (1,768)	$ (125)	$ (102)	$ 2,262	$ (351)	$ (1,646)	$ (10,337)	$ 163	$ (4,515)
Net unrealized gain (loss) on available-for-sale investments									108	105	(80)
Total comprehensive income (loss)									$ (10,229)	$ 268	$ (4,595)