PENSION AND OTHER POSTRETIREMENT BENEFITS

We have a noncontributory defined benefit pension plan covering substantially all employees first hired prior to July 1, 2015 after the completion of one year of service and 1,000 hours of service. The plan provides retirement benefits based on an employee’s average earnings and years of service. These employees become 100% vested after three years of service, regardless of age. A supplemental benefit plan provides nonqualified benefits for compensation in excess of the IRS compensation limits applicable to the plan.

Our plan funding policy is to make contributions, provided that the total annual contributions will not be less than ERISA and the Pension Protection Act of 2006 minimums or greater than the maximum tax-deductible amount, to review the contribution and funding strategy on a regular basis, and to allow discretionary contributions to be made by us from time to time. The assets of the defined benefit pension plan are invested primarily in fixed income investments and equity securities. We pay nonqualified pension benefits when they are due according to the terms of the supplemental benefit plan.

We provide certain postretirement health care and life insurance benefits to retired employees. Substantially all of our employees hired or rehired prior to 2014 may become eligible for postretirement medical benefits if they reach the age and service requirements of the retiree medical plan and retire on a service pension (except a deferred pension) under the defined benefit pension plan. Medical benefits are self-insured and claims are administered through an insurance company. The cost of coverage is determined based on the annual projected plan costs. The participant's premium or cost is determined based on Company guidelines. Postretirement life insurance benefits are insured through an insurance company. We fund postretirement benefits as incurred, and accordingly, there were no assets held in the postretirement benefits plan at June 30, 2016 and December 31, 2015.

The net periodic benefit cost for the three and six months ended June 30, 2016 and 2015 included the following components:



	Pension Benefits						Postretirement Benefits
	Three Months Ended June 30,						Three Months Ended June 30,
	Three Months Ended June 30,						Three Months Ended June 30,
Components of Net Periodic Benefit Cost	2016			2015			2016			2015
Service cost	$	6,309		$	6,304		$	569		$	577
Interest cost	7,006			6,251			740			713
Expected return on plan assets	(6,733		)	(7,123		)	—			—
Amortization of:
Net actuarial loss	4,632			5,090			154			271
Prior service cost (gain)	112			113			(540		)	(545		)
Net periodic benefit cost	$	11,326		$	10,635		$	923		$	1,016

	Pension Benefits						Postretirement Benefits
	Six Months Ended June 30,						Six Months Ended June 30,
	Six Months Ended June 30,						Six Months Ended June 30,
Components of Net Periodic Benefit Cost	2016			2015			2016			2015
Service cost	$	12,684		$	12,804		$	1,144		$	1,252
Interest cost	14,131			12,601			1,515			1,463
Expected return on plan assets	(13,508		)	(14,148		)	—			—
Amortization of:
Net actuarial loss	9,582			10,014			354			522
Prior service cost (gain)	212			226			(1,090		)	(1,090		)
Net periodic benefit cost	$	23,101		$	21,497		$	1,923		$	2,147

We made qualified and nonqualified pension contributions totaling $26,000 and $10,002 during the three-month periods ended June 30, 2016 and 2015, respectively. Contributions made during the six-month periods ending June 30, 2016 and 2015 totaled $37,631 and $21,534, respectively. Additional contributions totaling $44,004 are expected to be paid during the remainder of 2016.