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Concentrations of Risks (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Concentrations of Risks (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2019
Concentration of Risk
Accounts Payable, Trade, Current	$ 137,263		$ 137,263		$ 153,287
Accrued Liabilities, Current	143,977		143,977		93,761
Other non-current obligations	$ 148,835		$ 148,835		$ 125,360
Sales revenue \| Sales risk
Concentration of Risk
Concentration Risk, Customer	1	1	1	1
Sales revenue \| Sales risk \| Minimum [Member]
Concentration of Risk
Concentration risk, percentage	10.00%	10.00%	10.00%	10.00%
Sales revenue \| Electronics distributor risk
Concentration of Risk
Concentration risk, percentage	40.00%	41.40%	41.40%	41.50%
Accounts receivable \| Sales risk
Concentration of Risk
Concentration Risk, Customer	1	0	1	0
Accounts receivable \| Credit Concentration Risk [Member] \| Minimum [Member]
Concentration of Risk
Concentration risk, percentage	10.00%	10.00%	10.00%	10.00%
U.S. Class Action Complaint [Member]
Concentration of Risk
Litigation Settlement, Amount Awarded to Other Party	$ 62,000
30 days from date of settlement [Member] \| U.S. Class Action Complaint [Member]
Concentration of Risk
Litigation Settlement, Amount Awarded to Other Party	10,000
Gain (loss) Related to Litigation Settlement [Member] \| U.S. Class Action Complaint [Member]
Concentration of Risk
Litigation Settlement, Amount Awarded to Other Party	$ 62,000