Pension And Other Postretirement Benefit Plans (Tables)

9 Months Ended

Dec. 31, 2020

Retirement Benefits [Abstract]

Components of Company's Net Periodic Benefit Cost

The components of the Company’s net periodic benefit cost were as follows:

	Pension Benefits				Other Postretirement Benefits
	Three Months Ended December 31,				Three Months Ended December 31,
(in thousands of dollars)	2020		2019		2020		2019
Service cost	$	1,603	$	1,529	$	48	$	53
Interest cost	2,403		2,678		286		322
Expected return on plan assets	(3,676)		(4,151)		(24)		(24)
Net amortization and deferral	1,120		696		(139)		(154)
Net periodic benefit cost	$	1,450	$	752	$	171	$	197

	Pension Benefits				Other Postretirement Benefits
	Nine Months Ended December 31,				Nine Months Ended December 31,
(in thousands of dollars)	2020		2019		2020		2019
Service cost	$	4,691	$	4,595	$	145	$	159
Interest cost	7,316		8,125		859		986
Expected return on plan assets	(11,032)		(12,557)		(72)		(80)
Net amortization and deferral	3,361		2,092		(424)		(459)
Net periodic benefit cost	$	4,336	$	2,255	$	508	$	606