Defined contribution plans - We maintain various defined contribution pension plans. Company contributions are based on matching or other formulas. Defined contribution plan expense approximated $2.7 million in 2016, $2.5 million in 2017 and $3.1 million in 2018.

Defined benefit pension plans - We maintain a defined benefit pension plan in the U.S. We also maintain a plan in the United Kingdom related to a former disposed business unit in the U.K. The benefits under our defined benefit plans are based upon years of service and employee compensation. The plans are closed to new participants and no additional benefits accrue to existing plan participants. Our funding policy is to contribute annually the minimum amount required under ERISA (or equivalent non-U.S.) regulations plus additional amounts as we deem appropriate.

We expect to contribute approximately $1.5 million to all of our defined benefit pension plans during 2019. Benefit payments to all plan participants out of plan assets are expected to be the equivalent of:

The funded status of our defined benefit pension plans is presented in the table below.

	December 31,
	2017			2018
	(In thousands)
Change in projected benefit obligations (PBO):
Benefit obligations at beginning of the year	$	54,261		$	53,978
Interest cost		2,072			1,808
Participant contributions		5			5
Actuarial losses		596			(2,511	)
Settlement gain		(315	)		-
Change in currency exchange rates		908			(545	)
Benefits paid		(3,549	)		(3,486	)
Benefit obligations at end of the year		53,978			49,249

Change in plan assets:
Fair value of plan assets at beginning of the year		42,268			44,222
Actual return on plan assets		3,726			(2,237	)
Employer contributions		1,006			2,792
Participant contributions		5			5
Change in currency exchange rates		766			(670	)
Benefits paid		(3,549	)		(3,486	)
Fair value of plan assets at end of year		44,222			40,626
Funded status	$	(9,756	)	$	(8,623	)

Amounts recognized in the balance sheet:
Noncurrent pension asset	$	2,593		$	1,898
Accrued pension costs:
Current		(155	)		(132	)
Noncurrent		(12,194	)		(10,389	)
Total	$	(9,756	)	$	(8,623	)

Accumulated other comprehensive loss - actuarial losses, net	$	30,435		$	31,601
Total	$	20,679		$	22,978
Accumulated benefit obligations (ABO)	$	53,978		$	49,249

The amounts shown in the table above for actuarial losses (gains) at December 31, 2017 and 2018 have not been recognized as components of our periodic defined benefit pension cost as of those dates. These amounts will be recognized as components of our periodic defined benefit cost in future years. These amounts, net of deferred income taxes, are recognized in our accumulated other comprehensive income (loss) at December 31, 2017 and 2018. We expect that $1.6 million of the unrecognized actuarial losses will be recognized as a component of our periodic defined benefit pension cost in 2019.

The table below details the changes in other comprehensive income during 2016, 2017 and 2018.

	Years ended December 31,
	2016		2017		2018
	(In thousands)
Changes in plan assets and benefit obligations recognized in other comprehensive income (loss):
Net actuarial gain (loss) arising during the year	$	122	$	498	$	(2,709)
Amortization of unrecognized net actuarial loss		1,474		1,704		1,937

Total	$	1,596	$	2,202	$	(772)

The components of our net periodic defined benefit pension cost are presented in the table below. The amount shown below for the amortization of unrecognized actuarial losses in 2016, 2017 and 2018, net of deferred income taxes, was recognized as a component of our accumulated other comprehensive income (loss) at December 31, 2015, 2016 and 2017, respectively.

	Years ended December 31,
	2016			2017			2018
	(In thousands)
Net periodic pension cost:
Interest cost on PBO	$	2,302		$	2,072		$	1,808
Expected return on plan assets		(2,911	)		(2,770	)		(3,043	)
Recognized actuarial losses		1,474			1,704			1,937
Settlement cost		-			87			-

Total	$	865		$	1,093		$	702

Certain information concerning our defined benefit pension plans (including information concerning certain plans for which ABO exceeds the fair value of plan assets as of the indicated date) is presented in the table below.

	December 31,
	2017		2018
	(In thousands)
PBO at end of the year
U.S. plan	$	44,709	$	40,643
U.K. plan		9,269		8,606

Total	$	53,978	$	49,249
Fair value of plan assets at end of the year
U.S. plan	$	32,360	$	30,122
U.K. plan		11,862		10,504

Total	$	44,222	$	40,626
Plans for which the ABO exceeds plan assets (only our U.S. plan):
PBO	$	44,709	$	40,643
ABO		44,709		40,643
Fair value of plan assets		32,360		30,122

The weighted-average discount rate assumptions used in determining the actuarial present value of our benefit obligations as of December 31, 2017 and 2018 are 3.4% and 3.9%, respectively. Such weighted-average rates were determined using the projected benefit obligations at each date. Since our plans are closed to new participants and no new additional benefits accrue to existing plan participants, assumptions regarding future compensation levels are not applicable. Consequently, the accumulated benefit obligations for all of our defined benefit pension plans were equal to the projected benefit obligations at December 31, 2017 and 2018.

The weighted-average rate assumptions used in determining the net periodic pension cost for 2016, 2017 and 2018 are presented in the table below. Such weighted-average discount rates were determined using the projected benefit obligations as of the beginning of each year and the weighted-average long-term return on plan assets was determined using the fair value of plan assets as of the beginning of each year.

Variances from actuarially assumed rates will result in increases or decreases in accumulated pension obligations, pension expense and funding requirements in future periods.

At December 31, 2017, substantially all of the assets attributable to our U.S. plan were invested in the Combined Master Retirement Trust (CMRT), a collective investment trust sponsored by Contran to permit the collective investment by certain master trusts that fund certain employee benefit plans sponsored by Contran and certain of its affiliates, including us. For 2016, 2017 and 2018, the long-term rate of return assumption for our U.S. plan assets was 7.5%, based on the long-term asset mix of the assets of the CMRT and the expected long-term rates of return for such asset components as well as advice from Contran’s actuaries. During 2018, Contran and the other employer-sponsors (including us) implemented a restructuring of the CMRT, in which a substantial part of each plan’s units in the CMRT were redeemed in exchange for a pro-rata portion of a substantial part of the CMRT’s investments. Following such restructuring, the plans held directly in the aggregate the investments previously held directly by the CMRT which had been exchanged for CMRT units as part of the restructuring. Certain investments held directly by the CMRT were not part of such restructuring and remain investments of the CMRT. Such restructuring was implemented in part so each plan could more easily align the composition of their plan asset portfolio with the plan’s benefit obligations.

The CMRT unit value is determined semi-monthly, and prior to the 2018 restructuring, the plans had the ability to redeem all or any portion of their investment in the CMRT at any time based on the most recent semi-monthly valuation. However, the plans do not have the right to individual assets held by the CMRT and the CMRT has the sole discretion in determining how to meet any redemption request. For purposes of our plan asset disclosure, we consider the investment in the CMRT at December 31, 2017 as a Level 2 input because (i) the CMRT value is established semi-monthly and the plans have the right to redeem their investment in the CMRT, in part or in whole, at any time based on the most recent value and (ii) observable inputs from Level 1 or Level 2 (or assets not subject to classification in the fair value hierarchy) were used to value approximately 93% of the assets of the CMRT at December 31, 2017 as noted below. CMRT assets not subject to classification in the fair value hierarchy consist principally of certain investments measured at net asset value (NAV) per share in accordance with ASC 820-10. The aggregate fair value of all of the CMRT assets at December 31, 2017, including funds of Contran and its other affiliates that also invest in the CMRT, and supplemental asset mix details of the CMRT are as follows:

The assets which remain in the CMRT are principally common stocks and limited partnerships which are not publicly traded, most of which are categorized within Level 3 of the fair value hierarchy. As monetizing events occur for these investments, we and the other plans which hold units in the CMRT will redeem a portion of our CMRT units for the cash generated from such events. For purposes of our plan asset disclosure, we consider the investment in the CMRT at December 31, 2018 as a Level 3 input because (i) most of the remaining assets in the CMRT are categorized within Level 3 of the fair value hierarchy, and (ii) we do not expect to be able to redeem our remaining CMRT units until monetizing events occur with respect to the remaining CMRT assets.

In determining the expected long-term rate of return on our U.S. and non-U.S. plan asset assumptions, we consider the long-term asset mix (e.g. equity vs. fixed income) for the assets for each of our plans and the expected long-term rates of return for such asset components. In addition, we receive third-party advice about appropriate long-term rates of return. In the U.S. we currently have a plan asset target allocation of % to equity securities, % to fixed income securities, and the remainder is allocated to multi-asset strategies and the CMRT. The expected long-term rate of return for such investments is approximately , and , respectively (before plan administrative expenses). The majority of U.S. plan assets are Level 1 inputs because they are traded in active markets, approximately % of our U.S. plan assets are invested in funds that are valued at NAV and not subject to classification in the fair value hierarchy, and approximately % are invested in the CMRT which as noted above is a Level 3 input.

We regularly review our actual asset allocation for each plan, and will periodically rebalance the investments in each plan to more accurately reflect the targeted allocation and/or maximize the overall long-term return when considered appropriate.

		December 31,
		2017
		(In millions)
CMRT asset value	$	672.4
CMRT assets comprised of:
Assets not subject to fair value hierarchy		31	%
Assets subject to fair value hierarchy:
Level 1		54
Level 2		8
Level 3		7
		100	%
CMRT asset mix:
Domestic equities, principally publicly traded		33	%
International equities, principally publicly traded		25
Fixed income securities, principally publicly traded		31
Privately managed limited partnerships		4
Hedge funds		5
Other, primarily cash		2
		100	%

In determining the expected long-term rate of return on our U.S. and non-U.S. plan asset assumptions, we consider the long-term asset mix (e.g. equity vs. fixed income) for the assets for each of our plans and the expected long-term rates of return for such asset components. In addition, we receive third-party advice about appropriate long-term rates of return. In the U.S. we currently have a plan asset target allocation of 40% to equity securities, 45% to fixed income securities, and the remainder is allocated to multi-asset strategies and the CMRT. The expected long-term rate of return for such investments is approximately 9%, 5% and 3%, respectively (before plan administrative expenses). The majority of U.S. plan assets are Level 1 inputs because they are traded in active markets, approximately 29% of our U.S. plan assets are invested in funds that are valued at NAV and not subject to classification in the fair value hierarchy, and approximately 6% are invested in the CMRT which as noted above is a Level 3 input.

The composition of our pension plan assets by fair value level at December 31, 2017 and 2018 is shown in the table below. The amounts shown for plan assets invested in the CMRT include a nominal amount of cash held by our U.S. pension plan which is not part of the plan’s investment in the CMRT.

	Fair Value Measurements
	Total		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)
	(In thousands)
December 31, 2017:
CMRT	$	32,360	$	-	$	32,360
Other		11,862		11,862		-

Total	$	44,222	$	11,862	$	32,360

	Fair Value Measurements
	Total		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Assets measured at NAV
	(In thousands)
December 31, 2018:
U.S.
Equities	$	11,353	$	3,423	$	-	$	-	$	7,930
Fixed income		13,856		13,856		-		-		-
Cash and other		3,250		2,347		-		-		903
CMRT		1,663		-		-		1,663		-
Other		10,504		10,504		-		-		-
Total	$	40,626	$	30,130	$	-	$	1,663	$	8,833