Employee Benefit Plans (Table Text Block)	3 Months Ended	9 Months Ended
	Dec. 31, 2019	Dec. 31, 2019
Compensation and Retirement Disclosure [Abstract]
Components of Net Periodic Post Retirement Benefit Cost	Quarter Ended December 31,     2019   2018     (Unaudited)     (In thousands)           Service cost for benefits earned during the period $ 292 $ 277 Other components of net periodic benefit costs:         Interest cost on accumulated postretirement benefit   241   235 Other components   22   18 Total other components of net periodic benefit costs   263   253 Net periodic postretirement benefit cost $ 555 $ 530	Nine Months Ended December 31,     2019   2018     (Unaudited)     (In thousands)           Service cost for benefits earned during the period $ 876 $ 831 Other components of net periodic benefit costs:         Interest cost on accumulated postretirement benefit   723   707 Other components   67   53 Total other components of net periodic benefit costs   790   760 Net periodic postretirement benefit cost $ 1,666 $ 1,591