Retirement Plans (Tables)

12 Months Ended

Dec. 31, 2018

Compensation And Retirement Disclosure [Abstract]

Change in Benefit Obligation, Fair Value of Plan Assets, and Funded Status of Pension Plans and Postretirement Medical Plan

The following table summarizes the benefit obligations, the fair value of plan assets, and the funded status of our pension and postretirement medical plans:

	Funded						Unfunded						Postretirement
	Pension Plans						Pension Plan						Medical Plan
	2018			2017			2018			2017			2018			2017
	(In millions)
Change in Benefit Obligation
Balance at January 1,	$	2,765		$	2,560		$	249		$	256		$	87		$	84
Service cost		30			36			12			13			2			4
Interest cost		84			93			7			9			3			3
Actuarial (gains) loss (a)		(237	)		138			(29	)		10			(24	)		3
Benefit payments (b)		(110	)		(113	)		(19	)		(39	)		(7	)		(7	)
Plan curtailments		(10	)		(3	)		(4	)		—			(2	)		—
Plan amendments		4			—			—			—			—			—
Foreign currency exchange rate changes		(34	)		54			—			—			—			—
Balance at December 31, (c)		2,492			2,765			216			249			59			87
Change in Fair Value of Plan Assets
Balance at January 1,	$	2,732		$	2,284		$	—		$	—		$	—		$	—
Actual return on plan assets		(77	)		351			—			—			—			—
Employer contributions		59			158			19			39			7			7
Benefit payments (b)		(110	)		(113	)		(19	)		(39	)		(7	)		(7	)
Foreign currency exchange rate changes		(36	)		52			—			—			—			—
Balance at December 31,		2,568			2,732			—			—			—			—

Funded Status (Plan assets greater (less) than benefit obligations) at December 31,	$	76		$	(33	)	$	(216	)	$	(249	)	$	(59	)	$	(87	)

Unrecognized Net Actuarial (Gains) Losses	$	778		$	789		$	47		$	84		$	(32	)	$	(10	)

(a)	The change in discount rate in 2018 resulted in total actuarial gains of approximately $235 million (2017: $170 million of actuarial losses).

(b)	Benefit payments include lump-sum settlement payments of approximately $32 million in 2018 (2017: $57 million).

(c)	At December 31, 2018, the accumulated benefit obligation for the funded and unfunded defined benefit pension plans was $2,424 million and $171 million, respectively (2017: $2,679 million and $190 million, respectively).

Pension Plans and Postretirement Medical Plan Amounts Recognized in Consolidated Balance Sheet

Amounts recognized in the Consolidated Balance Sheet at December 31 consisted of the following:

	Funded					Unfunded						Postretirement
	Pension Plans					Pension Plan						Medical Plan
	2018		2017			2018			2017			2018			2017
	(In millions)
Noncurrent assets	$	76	$	22		$	—		$	—		$	—		$	—
Current liabilities		—		—			(30	)		(18	)		(9	)		(11	)
Noncurrent liabilities		—		(55	)		(186	)		(231	)		(50	)		(76	)
Pension assets / (accrued benefit liability)	$	76	$	(33	)	$	(216	)	$	(249	)	$	(59	)	$	(87	)

Accumulated other comprehensive loss, pre-tax (a)	$	778	$	789		$	47		$	84		$	(32	)	$	(10	)

(a)	The after‑tax deficit reflected in Accumulated other comprehensive income (loss) was $581 million at December 31, 2018 (2017: $548 million deficit).

Components of Net Periodic Benefit Cost for Funded and Unfunded Pension Plans and Postretirement Medical Plan

The net periodic benefit cost for funded and unfunded pension plans, and the postretirement medical plan, is as follows:

	Pension Plans									Postretirement Medical Plan
	2018			2017			2016			2018			2017		2016
	(In millions)
Service cost	$	42		$	49		$	60		$	2		$	4	$	4
Interest cost		91			102			107			3			3		3
Expected return on plan assets		(194	)		(168	)		(166	)		—			—		—
Amortization of unrecognized net actuarial losses (gains)		39			58			60			(2	)		—		—
Settlement loss		4			19			—			—			—		—
Curtailment gain		—			—			—			(2	)		—		—
Special termination benefit recognized		—			—			1			—			—		—
Net Periodic Benefit Cost (a)	$	(18	)	$	60		$	62		$	1		$	7	$	7

Actuarial Assumptions Used For Pension Plans & Postretirement Medical Plan

The weighted average actuarial assumptions used to determine Benefit obligations at December 31 and Net periodic benefit cost for the three years ended December 31 for our funded and unfunded pension plans were as follows:

	2018			2017			2016
Benefit Obligations:
Discount rate		3.9	%		3.3	%		3.7	%
Rate of compensation increase		3.8	%		4.5	%		4.6	%
Net Periodic Benefit Cost:
Discount rate
Service cost		3.9	%		3.7	%		4.1	%
Interest cost		3.3	%		3.7	%		4.1	%
Expected return on plan assets		7.2	%		7.3	%		7.4	%
Rate of compensation increase		4.5	%		4.6	%		4.5	%

The actuarial assumptions used to determine Benefit obligations at December 31 for the postretirement medical plan were as follows:

	2018			2017			2016
Discount rate		3.9	%		3.2	%		3.5	%
Initial health care trend rate		6.9	%		7.3	%		7.7	%
Ultimate trend rate		4.5	%		4.5	%		4.5	%
Year in which ultimate trend rate is reached		2038			2038			2038

Fair Value of Financial Assets of Funded Pension Plans

The following tables provide the fair value of the financial assets of the funded pension plans at December 31, 2018 and 2017 in accordance with the fair value measurement hierarchy described in Note 1, Nature of Operations, Basis of Presentation and Summary of Accounting Policies.

	Level 1		Level 2		Level 3		Net Asset Value (d)		Total
	(In millions)
December 31, 2018
Cash and Short-Term Investment Funds	$	3	$	47	$	—	$	—	$	50
Equities:
U.S. equities (domestic)		654		—		—		—		654
International equities (non-U.S.)		92		29		—		288		409
Global equities (domestic and non-U.S.)		2		203		—		—		205
Fixed Income:
Treasury and government issued (a)		—		240		—		—		240
Government related (b)		—		37		—		—		37
Mortgage-backed securities (c)		—		159		—		27		186
Corporate		—		272		—		31		303
Other:
Hedge funds		—		—		—		135		135
Private equity funds		—		—		—		170		170
Real estate funds		49		—		61		50		160
Diversified commodities funds		—		19		—		—		19
Total investments	$	800	$	1,006	$	61	$	701	$	2,568

December 31, 2017
Cash and Short-Term Investment Funds	$	32	$	69	$	—	$	—	$	101
Equities:
U.S. equities (domestic)		789		—		—		—		789
International equities (non-U.S.)		104		34		—		296		434
Global equities (domestic and non-U.S.)		2		238		—		—		240
Fixed Income:
Treasury and government issued (a)		—		271		—		—		271
Government related (b)		—		34		1		—		35
Mortgage-backed securities (c)		—		139		1		26		166
Corporate		—		182		—		6		188
Other:
Hedge funds		—		—		—		187		187
Private equity funds		—		—		—		140		140
Real estate funds		63		—		2		92		157
Diversified commodities funds		—		24		—		—		24
Total investments	$	990	$	991	$	4	$	747	$	2,732

(a)	Includes securities issued and guaranteed by U.S. and non‑U.S. governments.

(b)	Primarily consists of securities issued by governmental agencies and municipalities.

(c)	Comprised of U.S. residential and commercial mortgage-backed securities.

(d)

Includes certain investments that have been valued using the net asset value practical expedient, and therefore have not been categorized in the fair value hierarchy. The inclusion of such amounts in the above table is intended to aid reconciliation of investments categorized in the fair value hierarchy to total pension plan assets.

Changes in Financial Assets that are Measured at Fair Value Based on Level 3 Inputs that are held by Institutional Funds

The following tables provide changes in financial assets that are measured at fair value based on Level 3 inputs that are held by institutional funds classified as:

	Fixed			Real Estate
	Income			Funds			Total
	(In millions)
Balance at January 1, 2017	$	2		$	8		$	10
Actual return on plan assets		—			—			—
Purchases, sales or other settlements		1			(6	)		(5	)
Net transfers in (out) of Level 3		(1	)		—			(1	)
Balance at December 31, 2017		2			2			4
Actual return on plan assets		—			1			1
Purchases, sales or other settlements		(2	)		58			56
Net transfers in (out) of Level 3		—			—			—
Balance at December 31, 2018	$	—		$	61		$	61

Estimated Future Benefit Payments for Funded and Unfunded Pension Plans and Postretirement Medical Plan

Estimated future benefit payments by the funded and unfunded pension plans, and the postretirement medical plan, which reflect expected future service, are as follows (in millions):

2019	$	142
2020		139
2021		135
2022		139
2023		140
Years 2024 to 2028		722