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, 2017 and 2016:



	Three Months Ended June 30						Six Months Ended June 30
	2017			2016			2017			2016
	(In thousands)
Components of net periodic benefit cost:
Service cost	$	752		$	793		$	1,504		$	1,586
Interest cost	2,927			3,043			5,854			6,086
Expected return on plan assets	(4,758		)	(4,633		)	(9,516		)	(9,266		)
Amortizations:
Prior service cost	176			214			352			428
Unrecognized net loss	2,581			2,206			5,162			4,412
Net periodic benefit cost	$	1,678		$	1,623		$	3,356		$	3,246

On April 3, 2017, we made a discretionary contribution of $38.5 million to our company-sponsored pension plans. We expect to contribute an additional $0.8 million to the company-sponsored pension plans during the remainder of 2017.

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, 2017 and 2016:



	Three Months Ended June 30						Six Months Ended June 30
	2017			2016			2017			2016
	(In thousands)
Components of net periodic benefit cost:
Service cost	$	146		$	160		$	292		$	320
Interest cost	240			271			480			542
Amortizations:
Prior service cost	23			23			46			46
Unrecognized net gain	(114		)	(61		)	(228		)	(122		)
Net periodic benefit cost	$	295		$	393		$	590		$	786