Accumulated Other Comprehensive Income (Loss)	3 Months Ended
	Jun. 30, 2021
Disclosure Text Block [Abstract]
6. Comprehensive Income (Loss)	6. Accumulated Other Comprehensive Income (Loss) A summary of AOCI components, net of tax, were as follows:       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)     (Unaudited)     (In thousands) Balance at March 31, 2021 $ (52,929) $   167,653 $   (3,879) $   (3,988) $   106,857 Foreign currency translation   (3,392)   –   –   –   (3,392) Unrealized net losses on investments   –   (73,027)   –   –   (73,027) Change in fair value of cash flow hedges   –   –   (51)   –   (51) Amounts reclassified into earnings on hedging activities   –   –   745   –   745 Other comprehensive income (loss)   (3,392)   (73,027)   694   –   (75,725) Balance at June 30, 2021 $ ( 56,321 ) $   94,626 $   ( 3,185 ) $   ( 3,988 ) $   31,132