Employee Benefits

We maintain a number of active defined contribution retirement plans for our employees. The majority of our defined benefit plans are frozen. As a result, no new employees will be permitted to enter these plans and no additional benefits for current participants in the frozen plans will be accrued.

We have supplemental benefit plans that provide senior management with supplemental retirement, disability and death benefits. Certain supplemental retirement benefits are based on final monthly earnings. In addition, we sponsor voluntary 401(k) plans under which we may match employee contributions up to certain levels of compensation as well as profit-sharing plans under which we contribute a percentage of eligible employees' compensation to the employees' accounts.

We also provide certain medical, dental and life insurance benefits for active and retired employees and eligible dependents. The medical and dental plans and supplemental life insurance plan are contributory, while the basic life insurance plan is noncontributory. We currently do not prefund any of these plans.

We recognize the funded status of our defined benefit retirement and postretirement plans in the consolidated balance sheets, with a corresponding adjustment to accumulated other comprehensive loss, net of taxes. The amounts in accumulated other comprehensive loss represent unrecognized actuarial losses and unrecognized prior service costs. These amounts will be subsequently recognized as net periodic benefit (credit) cost pursuant to our accounting policy for amortizing such amounts.

The components of net periodic benefit (credit) cost for our retirement plans and postretirement plans for the periods ended June 30 are as follows:

Retirement Plans



(in millions)	Three Months						Six Months
	2016			2015			2016			2015
Service cost	$	1		$	2		$	1		$	3
Interest cost	19			24			39			48
Expected return on plan assets	(31		)	(32		)	(61		)	(63		)
Amortization of actuarial loss	4			5			8			10
Net periodic benefit (credit) cost	$	(7	)	$	(1	)	$	(13	)	$	(2	)

Postretirement Plans



(in millions)	Three Months						Six Months
	2016			2015			2016			2015
Service cost	$	—		$	—		$	—		$	—
Interest cost	1			1			1			2
Amortization of prior service credit / actuarial gain	(1		)	(1		)	(1		)	(1		)
Net periodic benefit (credit) cost	$	—		$	—		$	—		$	1

As discussed in our Form 10-K, we changed certain discount rate assumptions and our expected return on assets assumption for our retirement plans, which became effective on January 1, 2016. In addition, at the end of 2015, we changed our approach used to measure service and interest costs on all of our retirement plans. For 2015, we measured service and interest costs utilizing a single weighted-average discount rate derived from the yield curve used to measure the benefit obligation. For 2016, we elected to measure service and interest costs by applying the specific spot rates along that yield curve to the plans' liability cash flows. We also updated the assumed mortality rates to reflect life expectancy improvements. The effect of the assumption changes for the three and six months ended June 30, 2016 resulted in a decrease in net periodic benefit cost of approximately $5 million and $10 million respectively.

In the first six months of 2016, we contributed $4 million to our retirement plans and expect to make additional required contributions of approximately $4 million to our retirement plans during the remainder of the year. We may elect to make additional non-required contributions depending on investment performance and the pension plan status in the remaining second half of 2016.