RETIREMENT BENEFITS AND ASSETS HELD IN TRUST (Tables)

6 Months Ended

Jun. 30, 2016

Defined Benefit Plans

Defined Benefit Plan Disclosure

Schedule of Net Defined Benefit Cost Components

Net periodic benefit cost for the pension plans, by component, was as follows for the three and six months ended June 30, 2016 and 2015:

	Three months ended						Six months ended
	June 30,						June 30,
(in thousands)	2016			2015			2016			2015
Service cost	$	1,604		$	1,624		$	3,208		$	3,248
Interest cost	872			924			1,744			1,848
Expected return on plan assets	(932		)	(959		)	(1,864		)	(1,919		)
Amortization of prior service credit	(4		)	(11		)	(8		)	(21		)
Amortization of unrecognized loss	876			1,060			1,752			2,121
Net pension cost	$	2,416		$	2,638		$	4,832		$	5,277

Other Postretirement Benefits Plan

Defined Benefit Plan Disclosure

Schedule of Net Defined Benefit Cost Components

Net postretirement benefit plan cost, by component, was as follows for the three and six months ended June 30, 2016 and 2015:

	Three months ended						Six months ended
	June 30,						June 30,
(in thousands)	2016			2015			2016			2015
Service cost	$	1,855		$	2,121		$	3,710		$	4,243
Interest cost	630			619			1,260			1,238
Expected return on plan assets	(531		)	(463		)	(1,061		)	(926		)
Amortization of unrecognized loss	—			125			—			250
Net postretirement cost	$	1,954		$	2,402		$	3,909		$	4,805