Pension and Other Postretirement Plans (Tables)

9 Months Ended

Sep. 30, 2017

Defined Benefit Pension Plans

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

Schedule of Net Periodic Benefit Costs

The following table summarizes the components of net periodic benefit cost.

	Three Months Ended					Nine Months Ended
	September 30,					September 30,
	2017			2016		2017		2016
	(In thousands)
Service cost	$	27		26		81		79
Interest cost	240			250		718		750
Expected return on plan assets	(306		)	(304	)	(920	)	(912	)
Amortization of prior service cost	—			—		—		—
Amortization of net loss	159			193		477		579
Net periodic benefit cost	$	120		165		356		496

Chairman and President Non-Qualified Defined Benefit Plans

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

Schedule of Net Periodic Benefit Costs

The following table summarizes the components of net periodic benefit costs for the nonqualified defined benefit plans.

	Three Months Ended			Nine Months Ended
	September 30,			September 30,
	2017		2016	2017	2016
	(In thousands)
Service cost	$	204	109	612	327
Interest cost	347		265	1,041	794
Amortization of prior service cost	15		15	45	45
Amortization of net loss	818		501	2,455	1,503
Net periodic benefit cost	$	1,384	890	4,153	2,669

Defined Benefit Postretirement Healthcare Plans

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

Schedule of Net Periodic Benefit Costs

The following table summarizes the components of net periodic benefit costs.

	Three Months Ended			Nine Months Ended
	September 30,			September 30,
	2017		2016	2017	2016
	(In thousands)
Interest cost	$	35	30	104	90
Amortization of prior service cost	25		26	77	78
Amortization of net loss	10		—	31	—
Net periodic benefit cost	$	70	56	212	168