Schedule II — Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Allowance for doubtful accounts receivable
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, Beginning of Year	$ 54	$ 54	$ 16
Additions	0	0	54
Write-offs	0	0	(16)
Recoveries and Other Adjustments	0	0	0
Balance, End of Year	54	54	54
Deferred tax asset valuation allowance
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, Beginning of Year	301,393	294,860	282,824
Additions	22,580	9,028	15,189
Write-offs	(8,881)	(2,495)	(3,153)
Recoveries and Other Adjustments	0	0	0
Balance, End of Year	$ 315,092	$ 301,393	$ 294,860