Employee Retirement and Postretirement Benefits

We sponsor various defined benefit and defined contribution retirement plans, including various employee savings and profit sharing plans, and contribute to various multiemployer pension plans on behalf of our employees. All full-time union and non-union employees who have met requirements pursuant to the plans are eligible to participate in one or more of these plans.

Defined Benefit Plans — The benefits under our defined benefit plans are based on years of service and employee compensation. The following table sets forth the components of net periodic benefit cost for our defined benefit plans during the three and six months ended June 30, 2018 and 2017:



	Three Months Ended June 30						Six Months Ended June 30
	2018			2017			2018			2017
	(In thousands)
Components of net periodic benefit cost:
Service cost	$	732		$	752		$	1,464		$	1,504
Interest cost	2,828			2,927			5,656			5,854
Expected return on plan assets	(4,411		)	(4,758		)	(8,822		)	(9,516		)
Amortizations:
Prior service cost	108			176			216			352
Unrecognized net loss	2,130			2,581			4,260			5,162
Net periodic benefit cost	$	1,387		$	1,678		$	2,774		$	3,356

We do not expect to make any contributions to the company-sponsored pension plans in 2018.

Postretirement Benefits — Certain of our subsidiaries provide health care benefits to certain retirees who are covered under specific group contracts. The following table sets forth the components of net periodic benefit cost for our postretirement benefit plans during the three and six months ended June 30, 2018 and 2017:



	Three Months Ended June 30						Six Months Ended June 30
	2018			2017			2018			2017
	(In thousands)
Components of net periodic benefit cost:
Service cost	$	170		$	146		$	340		$	292
Interest cost	235			240			470			480
Amortizations:
Prior service cost	23			23			46			46
Unrecognized net gain	(118		)	(114		)	(236		)	(228		)
Net periodic benefit cost	$	310		$	295		$	620		$	590