Pension and postretirement benefits (Tables)

3 Months Ended

Mar. 31, 2018

Pension Plans, Defined Benefit [Member]

Schedule Of Net Benefit Costs Table Text Block

		Pension Plan				Benefit Restoration Plans
		Quarters ended March 31,				Quarters ended March 31,
(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		4,716		5,054		349		411
Total net periodic pension cost (benefit)	$	1,194	$	988	$	184	$	261

Other Postretirement Benefit Plans Defined Benefit [Member]

Schedule Of Net Benefit Costs Table Text Block

		Quarters ended March 31,
(In thousands)		2018		2017
Personnel costs:
Service cost	$	257	$	256
Other operating expenses:
Interest cost		1,390		1,426
Amortization of prior service cost		(867)		(950)
Amortization of net loss		321		142
Total postretirement cost	$	1,101	$	874