
12.	EMPLOYEE BENEFIT PLANS

Defined Benefit Plans

We have defined benefit pension plans, some of which are subject to collective bargaining agreements, that cover most of our employees. These plans provide eligible employees with retirement income based primarily on years of service and compensation during specific periods under final average pay and cash balance formulas. We fund our pension plans as required by local regulations. In the U.S., all qualified pension plans are subject to the Employee Retirement Income Security Act minimum funding standard. We typically do not fund or fully fund U.S. nonqualified and certain international pension plans that are not subject to funding requirements because contributions to these pension plans may be less economic and investment returns may be less attractive than our other investment alternatives.

We also provide health care and life insurance benefits for certain retired employees through our postretirement benefit plans. Most of our employees become eligible for these benefits if, while still working for us, they reach normal retirement age or take early retirement. These plans are unfunded, and retired employees share the cost with us. Individuals who became our employees as a result of an acquisition became eligible for other postretirement benefits under our plans as determined by the terms of the relevant acquisition agreement.

The changes in benefit obligation related to all of our defined benefit plans, the changes in fair value of plan assets^(a), and the funded status of our defined benefit plans as of and for the years ended were as follows (in millions):



	Pension Plans						Other Postretirement Benefit Plans
	December 31,						December 31,
	2017			2016			2017			2016
Changes in benefit obligation:
Benefit obligation as of beginning of year	$	2,567		$	2,365		$	302		$	336
Service cost	123			111			6			7
Interest cost	86			84			10			12
Participant contributions	—			—			9			8
Benefits paid	(158		)	(130		)	(28		)	(27		)
Actuarial (gain) loss	286			171			6			(35		)
Other	22			(34		)	1			1
Benefit obligation as of end of year	$	2,926		$	2,567		$	306		$	302

Changes in plan assets (a):
Fair value of plan assets as of beginning of year	$	2,097		$	1,947		$	—		$	—
Actual return on plan assets	363			165			—			—
Valero contributions	110			141			19			18
Participant contributions	—			—			9			8
Benefits paid	(158		)	(130		)	(28		)	(27		)
Other	16			(26		)	—			1
Fair value of plan assets as of end of year	$	2,428		$	2,097		$	—		$	—

Reconciliation of funded status (a):
Fair value of plan assets as of end of year	$	2,428		$	2,097		$	—		$	—
Less benefit obligation as of end of year	2,926			2,567			306			302
Funded status as of end of year	$	(498	)	$	(470	)	$	(306	)	$	(302	)

Accumulated benefit obligation	$	2,746		$	2,419		n/a			n/a

^{___________________________}

(a)

Plan assets include only the assets associated with pension plans subject to legal minimum funding standards. Plan assets associated with U.S. nonqualified pension plans are not included here because they are not protected from our creditors and therefore cannot be reflected as a reduction from our obligations under the pension plans. As a result, the reconciliation of funded status does not reflect the effect of plan assets that exist for all of our defined benefit plans. See Note 18 for the assets associated with certain U.S. nonqualified pension plans.

Amounts recognized in our balance sheet for our pension and other postretirement benefits plans include (in millions):



	Pension Plans						Other Postretirement Benefit Plans
	December 31,						December 31,
	2017			2016			2017			2016
Deferred charges and other assets, net	$	5		$	2		$	—		$	—
Accrued expenses	(14		)	(13		)	(19		)	(19		)
Other long-term liabilities	(489		)	(459		)	(287		)	(283		)
	$	(498	)	$	(470	)	$	(306	)	$	(302	)

The accumulated benefit obligations for certain of our pension plans exceed the fair values of the assets of those plans. For those plans, the following table presents the total projected benefit obligation, accumulated benefit obligation, and fair value of the plan assets (in millions).



	December 31,
	2017		2016
Projected benefit obligation	$	2,661	$	2,322
Accumulated benefit obligation	2,526		2,210
Fair value of plan assets	2,180		1,870

Benefit payments that we expect to pay, including amounts related to expected future services that we expect to receive, are as follows for the years ending December 31 (in millions):



	Pension Benefits		Other Postretirement Benefits
2018	$	162	$	19
2019	219		19
2020	184		19
2021	180		19
2022	185		19
2023-2027	1,074		93

We plan to contribute approximately $131 million to our pension plans, including discretionary contributions of $100 million, and $19 million to our other postretirement benefit plans during 2018.

The components of net periodic benefit cost (credit) related to our defined benefit plans were as follows (in millions):



	Pension Plans									Other Postretirement Benefit Plans
	Year Ended December 31,									Year Ended December 31,
	2017			2016			2015			2017			2016			2015
Service cost	$	123		$	111		$	109		$	6		$	7		$	8
Interest cost	86			84			98			10			12			14
Expected return on plan assets	(150		)	(139		)	(133		)	—			—			—
Amortization of:
Net actuarial (gain) loss	53			49			62			(3		)	(1		)	—
Prior service credit	(20		)	(20		)	(22		)	(16		)	(16		)	(18		)
Special charges (credits)	4			(7		)	7			—			—			—
Net periodic benefit cost (credit)	$	96		$	78		$	121		$	(3	)	$	2		$	4

Amortization of prior service credit shown in the preceding table was based on a straight-line amortization of the cost over the average remaining service period of employees expected to receive benefits under each respective plan. Amortization of the net actuarial (gain) loss shown in the preceding table was based on the straight-line amortization of the excess of the unrecognized (gain) loss over 10 percent of the greater of the projected benefit obligation or market-related value of plan assets (smoothed asset value) over the average remaining service period of active employees expected to receive benefits under each respective plan.

Pre-tax amounts recognized in other comprehensive income (loss) were as follows (in millions):



	Pension Plans									Other Postretirement Benefit Plans
	Year Ended December 31,									Year Ended December 31,
	2017			2016			2015			2017			2016			2015
Net gain (loss) arising during the year:
Net actuarial gain (loss)	$	(73	)	$	(145	)	$	24		$	(6	)	$	35		$	26
Prior service cost	(4		)	—			(22		)	—			—			—
Net (gain) loss reclassified into income:
Net actuarial (gain) loss	53			49			62			(3		)	(1		)	—
Prior service credit	(20		)	(20		)	(22		)	(16		)	(16		)	(18		)
Curtailment and settlement loss	4			—			7			—			—			—
Total changes in other comprehensive income (loss)	$	(40	)	$	(116	)	$	49		$	(25	)	$	18		$	8

The pre-tax amounts in accumulated other comprehensive loss that have not yet been recognized as components of net periodic benefit cost (credit) were as follows (in millions):



	Pension Plans						Other Postretirement Benefit Plans
	December 31,						December 31,
	2017			2016			2017			2016
Net actuarial (gain) loss	$	894		$	878		$	(57	)	$	(66	)
Prior service credit	(121		)	(145		)	(42		)	(58		)
Total	$	773		$	733		$	(99	)	$	(124	)

The following pre-tax amounts included in accumulated other comprehensive loss as of December 31, 2017 are expected to be recognized as components of net periodic benefit cost (credit) during the year ending December 31, 2018 (in millions):



	Pension Plans			Other Postretirement Benefit Plans
Amortization of net actuarial (gain) loss	$	66		$	(2	)
Amortization of prior service credit	(19		)	(11		)
Total	$	47		$	(13	)

The weighted-average assumptions used to determine the benefit obligations were as follows:



	Pension Plans				Other Postretirement Benefit Plans
	December 31,				December 31,
	2017		2016		2017		2016
Discount rate	3.58	%	4.08	%	3.72	%	4.26	%
Rate of compensation increase	3.86	%	3.81	%	n/a		n/a

The discount rate assumption used to determine the benefit obligations as of December 31, 2017 and 2016 for the majority of our pension plans and other postretirement benefit plans was based on the Aon Hewitt AA Only Above Median yield curve and considered the timing of the projected cash outflows under our plans. This curve was designed by Aon Hewitt to provide a means for plan sponsors to value the liabilities of their pension plans or postretirement benefit plans. It is a hypothetical double-A yield curve represented by a series of annualized individual discount rates with maturities from one-half year to 99 years. Each bond issue underlying the curve is required to have an average rating of double-A when averaging all available ratings by Moody’s Investor Services, Standard and Poor’s Ratings Service, and Fitch Ratings. Only the bonds representing the 50 percent highest yielding issuances among those with average ratings of double-A are included in this yield curve.

We based our discount rate assumption on the Aon Hewitt AA Only Above Median yield curve because we believe it is representative of the types of bonds we would use to settle our pension and other postretirement benefit plan liabilities as of those dates. We believe that the yields associated with the bonds used to develop this yield curve reflect the current level of interest rates.

The weighted-average assumptions used to determine the net periodic benefit cost were as follows:



	Pension Plans						Other Postretirement Benefit Plans
	Year Ended December 31,						Year Ended December 31,
	2017		2016		2015		2017		2016		2015
Discount rate	4.08	%	4.45	%	4.10	%	4.26	%	4.53	%	4.13	%
Expected long-term rate of return on plan assets	7.29	%	7.28	%	7.29	%	n/a		n/a		n/a
Rate of compensation increase	3.81	%	3.79	%	3.78	%	n/a		n/a		n/a

The assumed health care cost trend rates were as follows:



	December 31,
	2017		2016
Health care cost trend rate assumed for the next year	7.30	%	7.28	%
Rate to which the cost trend rate was assumed to decline (the ultimate trend rate)	5.00	%	5.00	%
Year that the rate reaches the ultimate trend rate	2026		2026

Assumed health care cost trend rates impact the amounts reported for retiree health care plans. A one percentage-point increase or decrease in assumed health care cost trend rates would have an immaterial effect on the total of service and interest cost components and on the accumulated postretirement benefit obligation on our postretirement benefits.

The following tables present the fair values of the assets of our pension plans (in millions) as of December 31, 2017 and 2016 by level of the fair value hierarchy. Assets categorized in Level 1 of the hierarchy are measured at fair value using a market approach based on quotations from national securities exchanges. Assets categorized in Level 2 of the hierarchy are measured at net asset value in a market that is not active. As previously noted, we do not fund or fully fund U.S. nonqualified and certain international pension plans that are not subject to funding requirements, and we do not fund our other postretirement benefit plans.



	Fair Value Measurements Using							Total as of December 31, 2017
	Level 1			Level 2		Level 3		Total as of December 31, 2017
Equity securities:
U.S. companies (a)	$	571		$	—	$	—	$	571
International companies	187			1		—		188
Preferred stock	4			—		—		4
Mutual funds:
International growth	118			—		—		118
Index funds (b)	85			—		—		85
Corporate debt instruments	—			272		—		272
Government securities:
U.S. Treasury securities	45			—		—		45
Other government securities	—			144		—		144
Common collective trusts (c)	—			621		—		621
Pooled separate accounts	—			192		—		192
Private funds	—			101		—		101
Insurance contract	—			18		—		18
Interest and dividends receivable	5			—		—		5
Cash and cash equivalents	85			1		—		86
Securities transactions payable, net	(22		)	—		—		(22		)
Total pension assets	$	1,078		$	1,350	$	—	$	2,428

^{___________________________}

See notes on page 109.



	Fair Value Measurements Using							Total as of December 31, 2016
	Level 1			Level 2		Level 3		Total as of December 31, 2016
Equity securities:
U.S. companies (a)	$	562		$	—	$	—	$	562
International companies	164			—		—		164
Preferred stock	3			—		—		3
Mutual funds:
International growth	90			—		—		90
Index funds (b)	230			—		—		230
Corporate debt instruments	—			280		—		280
Government securities:
U.S. Treasury securities	52			—		—		52
Other government securities	—			158		—		158
Common collective trusts (c)	—			434		—		434
Private funds	—			76		—		76
Insurance contract	—			18		—		18
Interest and dividends receivable	5			—		—		5
Cash and cash equivalents	56			16		—		72
Securities transactions payable, net	(47		)	—		—		(47		)
Total pension assets	$	1,115		$	982	$	—	$	2,097

^{__________________________________}


(a)	Equity securities are held in a wide range of industrial sectors, including consumer goods, information technology, healthcare, industrials, and financial services.


(b)	This class includes primarily investments in approximately 70 percent equities and 30 percent bonds as of December 31, 2017. As of December 31, 2016, the class included primarily investments in approximately 50 percent equities and 50 percent bonds.


(c)	This class includes primarily investments in approximately 80 percent equities and 20 percent bonds as of December 31, 2017. As of December 31, 2016, the class included primarily investments in approximately 90 percent equities and 10 percent bonds.

The investment policies and strategies for the assets of our pension plans incorporate a well-diversified approach that is expected to earn long-term returns from capital appreciation and a growing stream of current income. This approach recognizes that assets are exposed to risk and the market value of the pension plans’ assets may fluctuate from year to year. Risk tolerance is determined based on our financial ability to withstand risk within the investment program and the willingness to accept return volatility. In line with the investment return objective and risk parameters, the pension plans’ mix of assets includes a diversified portfolio of equity and fixed-income investments. Equity securities include international stocks and a blend of U.S. growth and value stocks of various sizes of capitalization. Fixed income securities include bonds and notes issued by the U.S. government and its agencies, corporate bonds, and mortgage-backed securities. The aggregate asset allocation is reviewed on an annual basis. As of December 31, 2017, the target allocations for plan assets under our primary pension plan are 70 percent equity securities and 30 percent fixed income investments.

The expected long-term rate of return on plan assets is based on a forward-looking expected asset return model. This model derives an expected rate of return based on the target asset allocation of a plan’s assets. The underlying assumptions regarding expected rates of return for each asset class reflect Aon Hewitt’s best expectations for these asset classes. The model reflects the positive effect of periodic rebalancing among diversified asset classes. We select an expected asset return that is supported by this model.

Defined Contribution Plans

We have defined contribution plans that cover most of our employees. Our contributions to these plans are based on employees’ compensation and/or a partial match of employee contributions to the plans. Our contributions to these defined contribution plans were $70 million, $67 million, and $65 million for the years ended December 31, 2017, 2016, and 2015, respectively.