Employee benefit plans (Tables)

12 Months Ended

Dec. 31, 2020

Employee benefit plans

Summary of changes in the benefit obligations, the plan assets and funded status

	Pension				Other Postretirement
	2020		2019		2020		2019
Change in benefit obligation:
Benefit obligation at beginning of year	$	583	$	519	$	14	$	13
Service cost		2		2		—		—
Interest cost		17		21		—		1
Actuarial losses		55		71		—		—
Benefits paid		(33)		(30)		—		—
Benefit obligation at end of year	$	624	$	583	$	14	$	14
Change in fair value of plan assets:
Fair value of plan assets at beginning of year	$	404	$	352	$	—	$	—
Actuarial return on plan assets		40		70		—		—
Employer contributions		34		12		—		—
Benefits paid		(31)		(28)		—		—
Expenses paid		(3)		(2)		—		—
Fair value of plan assets at end of year		444		404		—		—
Unfunded status at end of year	$	(180)	$	(179)	$	(14)	$	(14)
Liabilities recognized in the Consolidated Balance Sheets:
Accrued compensation and benefits	$	(1)	$	(1)	$	(1)	$	(1)
Pension and other postretirement benefits		(179)		(178)		(13)		(13)
	$	(180)	$	(179)	$	(14)	$	(14)

Summary of the accumulated other comprehensive income

	Pension				Other Postretirement
	2020		2019		2020		2019
Net (loss) gain	$	(110)	$	(70)	$	9	$	12

Schedule of weighted average assumptions used to determine the benefit obligations

	Pension					Other Postretirement
	2020			2019		2020		2019
Discount rate		2.2	%	3.0	%	2.2	%	3.0	%

Summary of the components of net periodic benefit cost

	Pension						Other Postretirement
	2020		2019		2018		2020		2019		2018
Interest cost	$	17	$	21	$	19	$	—	$	1	$	1
Expected return on plan assets		(24)		(24)		(27)		—		—		—
Amortization of net loss (gain)		1		—		—		—		(1)		(1)
Settlement gain		—		—		—		(4)		—		—
Expenses paid		2		2		2		—		—		—
Net periodic benefit cost	$	(4)	$	(1)	$	(6)	$	(4)	$	—	$	—

Summary of other changes in plan assets and benefit obligations recognized in other comprehensive income

	Pension						Other Postretirement
	2020		2019		2018		2020		2019		2018
Net loss (gain)	$	40	$	25	$	9	$	4	$	—	$	(2)
Amortization of net (loss) gain		(1)		—		—		—		1		1
Total recognized in other comprehensive loss (income)	$	39	$	25	$	9	$	4	$	1	$	(1)
Total recognized in net periodic benefit cost (credit) and other comprehensive loss (income)	$	35	$	24	$	3	$	—	$	1	$	(1)

Schedule of weighted average assumptions used to determine the net periodic benefit cost

	Pension							Other Postretirement
	2020			2019		2018		2020			2019		2018
Discount rate		3.0	%	4.1	%	3.4	%		3.0	%	4.1	%	3.4	%
Expected long-term return on plan assets		6.5	%	7.0	%	7.0	%		N/A		N/A		N/A

Schedule of pension plan asset allocation

Asset Allocation	Target			Actual
Cash and cash equivalents		1	%		1	%
U.S. and global equity securities		71	%		71	%
Fixed income		28	%		28	%
		100	%		100	%

Schedule of fair value of pension plan assets by asset category segregated by level within the fair value hierarchy

	December 31, 2020								December 31, 2019
Asset Category	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Cash and cash equivalents	$	3	$	—	$	—	$	3	$	5	$	—	$	—	$	5
International equity securities		—		—		—		—		—		—		1		1
Commingled funds 1								441								398
Total assets at fair value	$	3	$	—	$	—	$	444	$	5	$	—	$	1	$	404

¹ Investments that are measured at fair value using the net asset value per share (or its equivalent) as a practical expedient are not required to be classified in the fair value hierarchy table. The total fair value of these amounts are presented in this table to permit reconciliation of the fair value hierarchy to the amounts presented for total defined benefit pension plan assets.

Schedule of expected benefit payments to be paid

		2021		2022		2023		2024		2025		2025 through 2029
Pension	$	31	$	32	$	32	$	32	$	32	$	159
Other postretirement		1		1		1		1		1		5
	$	32	$	33	$	33	$	33	$	33	$	164