Pension and postretirement benefits (Tables)

6 Months Ended

Jun. 30, 2018

Pension Plans, Defined Benefit [Member]

Schedule Of Net Benefit Costs Table Text Block

		Pension Plan				Benefit Restoration Plans
		Quarters ended June 30,				Quarters ended June 30,
(In thousands)		2018		2017		2018		2017
Other operating expenses:
Interest cost	$	6,029	$	6,120	$	344	$	352
Expected return on plan assets		(9,551)		(10,186)		(509)		(502)
Amortization of net loss		4,715		5,053		349		411
Total net periodic pension cost (benefit)	$	1,193	$	987	$	184	$	261

		Pension Plans				Benefit Restoration Plans
		Six months ended June 30,				Six months ended June 30,
(In thousands)		2018		2017		2018		2017
Other operating expenses:
Interest cost	$	12,058	$	12,240	$	688	$	705
Expected return on plan assets		(19,101)		(20,372)		(1,018)		(1,005)
Amortization of net loss		9,431		10,107		699		822
Total net periodic pension cost (benefit)	$	2,388	$	1,975	$	369	$	522

Other Postretirement Benefit Plans Defined Benefit [Member]

Schedule Of Net Benefit Costs Table Text Block

		Postretirement Benefit Plan
		Quarters ended June 30,				Six months ended June 30,
(In thousands)		2018		2017		2018		2017
Personnel Costs:
Service cost	$	257	$	256	$	514	$	513
Other operating expenses:
Interest cost		1,390		1,426		2,780		2,851
Amortization of prior service cost		(868)		(950)		(1,735)		(1,900)
Amortization of net loss		321		142		641		284
Total postretirement cost	$	1,100	$	874	$	2,200	$	1,748