Income Taxes - Components of income tax (benefit) expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Components of income tax (benefit) expense
Current income tax expense	$ 133	$ 220	$ 52
Deferred income tax expense (benefit)	1,061	1,232	(781)
Benefit of operating loss carryforwards	(1,238)	(1,316)	(87)
Recording of valuation allowance		8,943
Net income tax (benefit) provision	$ (44)	$ 9,079	$ (816)