Schedule II VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Valuation and qualifying accounts
Balance at Beginning of Year	$ 33,462	$ 32,354
Balance at End of Year	18,824	33,462	$ 32,354
Allowance for doubtful accounts
Valuation and qualifying accounts
Balance at Beginning of Year	3,487	5,979	5,494
Additions	2,849	4,168	2,847
Deductions	(1,263)	(6,660)	(2,362)
Balance at End of Year	5,073	3,487	5,979
Allowance for sales discounts
Valuation and qualifying accounts
Balance at Beginning of Year	1,400	3,100	2,672
Additions	11,712	19,972	20,259
Deductions	(12,402)	(21,672)	(19,831)
Balance at End of Year	710	1,400	3,100
Allowance for chargebacks
Valuation and qualifying accounts
Balance at Beginning of Year	7,727	7,028	4,968
Additions	23,369	19,019	19,584
Deductions	(18,055)	(18,320)	(17,524)
Balance at End of Year	13,041	7,727	7,028
Allowance for sales returns
Valuation and qualifying accounts
Balance at Beginning of Year	20,848	16,247	17,061
Additions	0	51,677	62,122
Deductions	(20,848)	(47,076)	(62,936)
Balance at End of Year	$ 0	$ 20,848	$ 16,247