Pension And Other Postretirement Benefit Plans (Tables)

3 Months Ended

Jun. 30, 2019

Defined Benefit Plan [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 June 30,						Three Months Ended June 30,
(in thousands of dollars)	2019			2018			2019			2018
Service cost	$	1,589		$	1,455		$	53		$	59
Interest cost	2,737			2,481			333			340
Expected return on plan assets	(4,216		)	(3,694		)	(27		)	(25		)
Net amortization and deferral	698			902			(152		)	(194		)
Net periodic benefit cost	$	808		$	1,144		$	207		$	180