Accumulated Other Comprehensive Income (Table Text Block)	12 Months Ended
	Mar. 31, 2021
Table Text Block [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Foreign Currency Translation   Unrealized Net Gain on Investments   Fair Value of Cash Flow Hedges   Postretirement Benefit Obligation Net Loss   Accumulated Other Comprehensive Income (Loss)           (In thousands) Balance as of March 31, 2020 $ (47,235) $ 90,684 $ (6,196) $ (2,601) $ 34,652 Foreign currency translation   (5,694)   -   -   -   (5,694) Unrealized net gain on investments   -   76,969   -   -   76,969 Change in fair value of cash flow hedges   -   -   (429)   -   (429) Amounts reclassified into earnings on hedging activities   -   -   2,746   -   2,746 Change in post retirement benefit obligaitons   -   -   -   (1,387)   (1,387) Other comprehensive income (loss)   (5,694)   76,969   2,317   (1,387)   72,205 Balance as of March 31, 2021 $ (52,929) $ 167,653 $ (3,879) $ (3,988) $ 106,857