Pension And Other Postretirement Benefit Plans (Tables)

9 Months Ended

Dec. 31, 2016

Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [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)	2016			2015			2016			2015
Service cost	$	1,343		$	1,469		$	73		$	106
Interest cost	2,453			2,345			378			387
Expected return on plan assets	(3,584		)	(3,574		)	(11		)	(15		)
Net amortization and deferral	843			1,201			(100		)	(44		)
Net periodic benefit cost	$	1,055		$	1,441		$	340		$	434

	Pension Benefits						Other Postretirement Benefits
	Nine Months Ended December 31,						Nine Months Ended December 31,
(in thousands of dollars)	2016			2015			2016			2015
Service cost	$	4,063		$	4,431		$	220		$	320
Interest cost	7,389			7,038			1,136			1,186
Expected return on plan assets	(10,762		)	(10,727		)	(33		)	(45		)
Net amortization and deferral	2,519			3,599			(300		)	(132		)
Net periodic benefit cost	$	3,209		$	4,341		$	1,023		$	1,329