Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (17,472)	$ (26,428)	$ (46,815)	$ (88,932)
Other comprehensive income (loss):
Cumulative translation adjustments	(525)	559	(1,086)	(2,149)
Changes in market value of investments:
Changes in unrealized gains (losses), net of taxes (benefit) of $5, ($20), $11 and $9, respectively	2	(5)	37	23
Total net change in market value of investments	2	(5)	37	23
Changes in market value of derivatives:
Changes in market value of derivatives, net of benefit of $22, $14, $41 and $140, respectively	(5)		(60)
Changes in market value of derivatives, net of benefit of $22, $14, $41 and $140, respectively		(45)		(438)
Reclassification adjustment for net gains included in net loss, net of taxes of $11, $49, $21 and $72, respectively	13		49
Reclassification adjustment for net gains included in net loss, net of taxes of $11, $49, $21 and $72, respectively		153		224
Total net change in market value of derivatives	8		(11)
Total net change in market value of derivatives	8	108	(11)	(214)
Other comprehensive (loss) income	(515)	662	(1,060)	(2,340)
Total comprehensive loss	$ (17,987)	$ (25,766)	$ (47,875)	$ (91,272)