Pension Plans, Retirement Benefits and Savings Plans (Tables)

12 Months Ended

Dec. 31, 2021

Retirement Benefits [Abstract]

Summary of the funded status, obligations and amounts recognized in the consolidated balance sheet for the Company's benefit plans [Table Text Block]

The following tables summarize the funded status, obligations and amounts recognized in the consolidated balance sheet for the Company’s benefit plans. The Company uses a December 31 measurement date for its pension and postretirement benefit plans.

(at and for the year ended December 31,  in millions)	Qualified Domestic Pension Plan				Nonqualified and Foreign Pension Plans				Total
	2021		2020		2021		2020		2021		2020
Change in projected benefit obligation:
Benefit obligation at beginning of year	$	4,326	$	3,954	$	265	$	241	$	4,591	$	4,195
Benefits earned	135		128		6		5		141		133
Interest cost on benefit obligation	79		109		4		5		83		114
Actuarial (gain) loss	(73)		336		(2)		20		(75)		356
Benefits paid	(255)		(201)		(13)		(11)		(268)		(212)
Amendment	—		—		—		1		—		1
Foreign currency exchange rate change	—		—		(1)		4		(1)		4
Benefit obligation at end of year	$	4,212	$	4,326	$	259	$	265	$	4,471	$	4,591
Change in plan assets:
Fair value of plan assets at beginning of year	$	4,631	$	4,270	$	125	$	115	$	4,756	$	4,385
Actual return on plan assets	526		562		11		8		537		570
Company contributions	—		—		12		9		12		9
Benefits paid	(255)		(201)		(13)		(11)		(268)		(212)
Foreign currency exchange rate change	—		—		(1)		4		(1)		4
Fair value of plan assets at end  of year	4,902		4,631		134		125		5,036		4,756
Funded status of plan at end  of year	$	690	$	305	$	(125)	$	(140)	$	565	$	165
Amounts recognized in the consolidated balance sheet consist of:
Accrued over-funded benefit plan assets	$	690	$	305	$	6	$	1	$	696	$	306
Accrued under-funded benefit plan liabilities	—		—		(131)		(141)		(131)		(141)
Total	$	690	$	305	$	(125)	$	(140)	$	565	$	165
Amounts recognized in accumulated other comprehensive income consist of:
Net actuarial loss	$	618	$	1,050	$	49	$	63	$	667	$	1,113
Prior service cost (benefit)	(2)		(2)		1		1		(1)		(1)
Total	$	616	$	1,048	$	50	$	64	$	666	$	1,112

	Postretirement Benefit Plans
(at and for the year ended December 31, in millions)	2021		2020
Change in accumulated benefit obligation:
Benefit obligation at beginning of year	$	171	$	171
Benefits earned	—		—
Interest cost on benefit obligation	3		4
Actuarial (gain) loss	(16)		5
Benefits paid	(9)		(10)
Foreign currency exchange rate change	—		1
Benefit obligation at end of year	$	149	$	171
Change in plan assets:
Fair value of plan assets at beginning of year	$	11	$	12
Actual return on plan assets	—		1
Company contributions	7		8
Benefits paid	(9)		(10)
Fair value of plan assets at end of year	9		11
Funded status of plan at end of year	$	(140)	$	(160)
Amounts recognized in the consolidated balance sheet consist of:
Accrued under-funded benefit plan liability	$	(140)	$	(160)
Amounts recognized in accumulated other comprehensive income consist of:
Net actuarial gain	$	(54)	$	(41)
Prior service benefit	(14)		(18)
Total	$	(68)	$	(59)

Summary of the components of net periodic benefit cost (benefit) and other amounts recognized in other comprehensive income (loss) related to the benefit plans [Table Text Block]

The following table summarizes the components of net periodic benefit cost (benefit) and other amounts recognized in other comprehensive income (loss) related to the benefit plans.

	Pension Plans						Postretirement Benefit Plans
(for the year ended December 31, in millions)	2021		2020		2019		2021		2020		2019
Net Periodic Benefit Cost (Benefit):
Service cost	$	141	$	133	$	118	$	—	$	—	$	—
Non-service cost (benefit):
Interest cost on benefit obligation	83		114		141		3		4		7
Expected return on plan assets	(274)		(275)		(275)		—		—		(1)
Amortization of unrecognized:
Prior service benefit	(1)		(1)		(1)		(4)		(3)		(3)
Net actuarial (gain) loss	109		93		56		(2)		(4)		—
Total non-service cost (benefit)	(83)		(69)		(79)		(3)		(3)		3
Net periodic benefit cost (benefit)	58		64		39		(3)		(3)		3
Other Changes in Benefit Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income:
Prior service benefit	—		1		—		—		—		—
Net actuarial (gain) loss	(338)		61		49		(16)		4		(31)
Foreign currency exchange rate change	—		1		1		—		—		—
Amortization of prior service benefit	1		1		1		4		3		3
Amortization of net actuarial gain (loss)	(109)		(93)		(56)		2		4		—
Total other changes recognized in other comprehensive income	(446)		(29)		(5)		(10)		11		(28)
Total other changes recognized in net periodic benefit cost and other comprehensive income	$	(388)	$	35	$	34	$	(13)	$	8	$	(25)

Consolidated statement of income line items impacted by service costs and non-service cost (benefit) [Table Text Block]

The following table indicates the line items in which the respective service costs and non-service cost (benefit) are presented in the consolidated statement of income for the years ended December 31, 2021, 2020 and 2019.

	Pension Plans						Postretirement Benefit Plans
(for the year ended December 31, in millions)	2021		2020		2019		2021		2020		2019
Service Cost:
Net investment income	$	1	$	1	$	1	$	—	$	—	$	—
Claims and claim adjustment expenses	57		55		48		—		—		—
General and administrative expenses	83		77		69		—		—		—
Total service cost	141		133		118		—		—		—
Non-Service Cost (Benefit):
Claims and claim adjustment expenses	(34)		(29)		(33)		(1)		(1)		1
General and administrative expenses	(49)		(40)		(46)		(2)		(2)		2
Total non-service cost (benefit)	(83)		(69)		(79)		(3)		(3)		3
Net periodic benefit cost (benefit)	$	58	$	64	$	39	$	(3)	$	(3)	$	3

Benefit obligations assumptions, net periodic benefit cost assumptions and health care cost trend rates [Table Text Block]

The following table summarizes assumptions used with regard to the Company’s qualified and nonqualified domestic pension plans and the domestic postretirement benefit plans.

(at and for the year ended December 31,)	2021		2020
Assumptions used to determine benefit obligations
Discount rate:
Qualified domestic pension plan	2.96	%	2.60	%
Nonqualified domestic pension plan	2.82	%	2.44	%
Domestic postretirement benefit plan	2.62	%	2.27	%
Cash balance interest crediting rate	4.01	%	4.01	%
Future compensation increase rate	4.00	%	4.00	%
Assumptions used to determine net periodic benefit cost
Discount rate:
Qualified domestic pension plan:
Service cost	2.96	%	3.50	%
Interest cost	1.88	%	2.84	%
Nonqualified domestic pension plan:
Service cost	2.58	%	3.30	%
Interest cost	1.69	%	2.73	%
Domestic postretirement benefit plan:
Interest cost	1.57	%	2.67	%
Expected long-term rate of return on assets:
Pension plan	6.50	%	6.75	%
Postretirement benefit plan	4.00	%	4.00	%
Assumed health care cost trend rates
Following year:
Medical (before age 65)	6.50	%	6.75	%
Medical (age 65 and older)	8.00	%	7.75	%
Rate to which the cost trend rate is assumed to decline (ultimate trend rate)	4.50	%	4.50	%
Year that the rate reaches the ultimate trend rate:
Medical (before age 65)	2029		2026
Medical (age 65 and older)	2031		2027

Level within the fair value hierarchy at which the financial assets of the Company's pension plans are measured [Table Text Block]

The following tables present the level within the fair value hierarchy at which the financial assets of the Company’s pension plans are measured on a recurring basis.

(at December 31, 2021, in millions)	Total		Level 1		Level 2		Level 3
Invested assets:
Fixed maturities
Obligations of states, municipalities and political subdivisions	$	26	$	—	$	26	$	—
Debt securities issued by foreign governments	38		—		38		—
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities	6		—		6		—
All other corporate bonds	678		—		678		—
Total fixed maturities	748		—		748		—
Mutual funds
Equity mutual funds	1,645		1,638		7		—
Bond mutual funds	1,114		1,111		3		—
Total mutual funds	2,759		2,749		10		—
Equity securities	1,385		1,384		1		—
Other investments	1		—		—		1
Cash and short-term securities
U.S. Treasury securities	—		—		—		—
Other	143		106		37		—
Total cash and short-term securities	143		106		37		—
Total	$	5,036	$	4,239	$	796	$	1

(at December 31, 2020, in millions)	Total		Level 1		Level 2		Level 3
Invested assets:
Fixed maturities
Obligations of states, municipalities and political subdivisions	$	27	$	—	$	27	$	—
Debt securities issued by foreign governments	30		—		30		—
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities	14		—		14		—
All other corporate bonds	712		—		712		—
Total fixed maturities	783		—		783		—
Mutual funds
Equity mutual funds	1,706		1,699		7		—
Bond mutual funds	949		946		3		—
Total mutual funds	2,655		2,645		10		—
Equity securities	1,171		1,171		—		—
Other investments	1		—		—		1
Cash and short-term securities
U.S. Treasury securities	—		—		—		—
Other	146		54		92		—
Total cash and short-term securities	146		54		92		—
Total	$	4,756	$	3,870	$	885	$	1

Estimated future benefit payments [Table Text Block]

The following table presents the estimated benefits expected to be paid by the Company’s pension and postretirement benefit plans for the next ten years (reflecting estimated future employee service).

	Benefits Expected to be Paid
(in millions)	Pension Plans		Postretirement Benefit Plans
2022	$	270	$	10
2023	273		11
2024	273		11
2025	272		11
2026	279		11
2027 through 2031	1,372		49