Employee benefit plans

Pension and other postretirement plans

The Company has noncontributory defined benefit pension plans and other postretirement benefit plans for certain eligible employees. Components of net periodic benefit cost (credit) for the Company's pension and other postretirement benefit plans were as follows:



	Pension Benefits						Other Postretirement Benefits
Three Months Ended June 30,	2017			2016			2017			2016
	(In thousands)
Components of net periodic benefit cost (credit):
Service cost	$	—		$	—		$	306		$	374
Interest cost	4,089			4,220			825			895
Expected return on assets	(5,234		)	(5,182		)	(1,175		)	(1,118		)
Amortization of prior service credit	—			—			(343		)	(343		)
Amortization of net actuarial loss	1,385			1,514			100			299
Net periodic benefit cost (credit), including amount capitalized	240			552			(287		)	107
Less amount capitalized	73			121			(114		)	4
Net periodic benefit cost (credit)	$	167		$	431		$	(173	)	$	103



	Pension Benefits						Other Postretirement Benefits
Six Months Ended June 30,	2017			2016			2017			2016
	(In thousands)
Components of net periodic benefit cost (credit):
Service cost	$	—		$	—		$	753		$	824
Interest cost	8,103			8,610			1,633			1,844
Expected return on assets	(10,263		)	(10,462		)	(2,320		)	(2,267		)
Amortization of prior service credit	—			—			(686		)	(686		)
Amortization of net actuarial loss	3,178			3,107			436			747
Net periodic benefit cost (credit), including amount capitalized	1,018			1,255			(184		)	462
Less amount capitalized	180			202			(153		)	38
Net periodic benefit cost (credit)	$	838		$	1,053		$	(31	)	$	424

Nonqualified benefit plans

In addition to the qualified plan defined pension benefits reflected in the table, the Company also has unfunded, nonqualified benefit plans for executive officers and certain key management employees that generally provide for defined benefit payments at age 65 following the employee's retirement or, upon death, to their beneficiaries for a 15-year period. In February 2016, the Company froze the unfunded, nonqualified defined benefit plans to new participants and eliminated benefit increases. Vesting for participants not fully vested was retained. The Company's net periodic benefit cost for these plans for the three and six months ended June 30, 2017, was $1.1 million and $2.3 million, respectively. The Company's net periodic benefit cost for these plans for the three months ended June 30, 2016, was $1.2 million. The Company's net periodic benefit credit for these plans for the six months ended June 30, 2016, was $700,000, which reflects a curtailment gain of $3.3 million in the first quarter of 2016.