Employee Benefit Plans	6 Months Ended
	Sep. 30, 2021
Compensation and Retirement Disclosure [Abstract]
13. Employee Benefit Plans	13. Employee Benefit Plans The components of the net periodic benefit costs with respect to postretirement benefits were as follows:     Quarter Ended September 30,     2021   2020     (Unaudited)     (In thousands)           Service cost for benefits earned during the period $ 351 $   316 Other components of net periodic benefit costs:         Interest cost on accumulated postretirement benefit   227   229 Other components   53   17 Total other components of net periodic benefit costs   280   246 Net periodic postretirement benefit cost $ 631 $   562       Six Months Ended September 30,     2021   2020     (Unaudited)     (In thousands)           Service cost for benefits earned during the period $ 701 $   633 Other components of net periodic benefit costs:         Interest cost on accumulated postretirement benefit   454   459 Other components   106   34 Total other components of net periodic benefit costs   560   493 Net periodic postretirement benefit cost $ 1,261 $   1,126