Accumulated Other Comprehensive Income (Table Text Block)	12 Months Ended
	Mar. 31, 2020
Table Text Block [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Foreign Currency Translation   Unrealized Net Gain on Investments   Fair Market Value of Cash Flow Hedges   Postretirement Benefit Obligation Net Loss   Accumulated Other Comprehensive Income (Loss)           (In thousands) Balance as of March 31, 2019 $ (56,612) $ (7,259) $ 107 $ (2,934) $ (66,698) Foreign currency translation   9,377   –   –   –   9,377 Unrealized net gain on investments   –   97,943   –   –   97,943 Change in fair value of cash flow hedges   –   –   (6,301)   –   (6,301) Amounts reclassified into earnings on hedging activities   –   –   (2)   –   (2) Change in post retirement benefit obligaiton   –   –   –   333   333 Other comprehensive income (loss)   9,377   97,943   (6,303)   333   101,350 Balance as of March 31, 2020 $ (47,235) $ 90,684 $ (6,196) $ (2,601) $ 34,652