Retirement Plans (Retirement Plans, Funded Status) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Expense for the defined contribution plans for continuing operations		$ 100	$ 206	$ 193
Foreign Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at end of period		1,200	1,100
Fair value of plan assets at end of period		1,077	1,002
Funded status at end of period		152	111
Defined Benefit Plan, Accumulated Benefit Obligation		1,100	1,000
Amounts recognized on the Consolidated Balance Sheets
Other Assets		45	85
Accrued employee compensation and benefits		8	7
Employee compensation and benefits		189	189
Pension plans in which projected benefit obligation exceeded plan assets
Projected benefit obligation		228	214
Fair value of plan assets		31	18
Pension plans in which accumulated benefit obligation exceeded plan assets
Accumulated benefit obligation		126	121
Fair value of plan assets		25	18
Foreign Plan [Member] | Cash and equivalents
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period		136	151
Foreign Plan [Member] | Equity funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[1]	170	118
Foreign Plan [Member] | Bond funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[2]	468	391
Foreign Plan [Member] | Alternatives fund
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[3]	167	197
Foreign Plan [Member] | Real estate funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[4]	96	103
Foreign Plan [Member] | Other investments
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[5]	40	42
Foreign Plan [Member] | Level 1
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period		5	6
Foreign Plan [Member] | Level 1 | Cash and equivalents
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period		0	0
Foreign Plan [Member] | Level 1 | Equity funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[1]	0	0
Foreign Plan [Member] | Level 1 | Bond funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[2]	0	0
Foreign Plan [Member] | Level 1 | Alternatives fund
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[3]	0	0
Foreign Plan [Member] | Level 1 | Real estate funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[4]	0	0
Foreign Plan [Member] | Level 1 | Other investments
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[5]	5	6
Foreign Plan [Member] | Level 2
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period		718	656
Foreign Plan [Member] | Level 2 | Cash and equivalents
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period		136	151
Foreign Plan [Member] | Level 2 | Equity funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[1]	170	118
Foreign Plan [Member] | Level 2 | Bond funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[2]	319	292
Foreign Plan [Member] | Level 2 | Alternatives fund
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[3]	4	0
Foreign Plan [Member] | Level 2 | Real estate funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[4]	68	74
Foreign Plan [Member] | Level 2 | Other investments
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[5]	21	21
Foreign Plan [Member] | Level 3
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period		14	15
Foreign Plan [Member] | Level 3 | Cash and equivalents
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period		0	0
Foreign Plan [Member] | Level 3 | Equity funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[1]	0	0
Foreign Plan [Member] | Level 3 | Bond funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[2]	0	0
Foreign Plan [Member] | Level 3 | Alternatives fund
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[3]	0	0
Foreign Plan [Member] | Level 3 | Real estate funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[4]	0	0
Foreign Plan [Member] | Level 3 | Other investments
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[5]	14	15
Foreign Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[6]	340	325
Foreign Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | Cash and equivalents
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[6]	0	0
Foreign Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | Equity funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[1],[6]	0	0
Foreign Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | Bond funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[2],[6]	149	99
Foreign Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | Alternatives fund
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[3],[6]	163	197
Foreign Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | Real estate funds
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[4],[6]	28	29
Foreign Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | Other investments
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	[5],[6]	$ 0	$ 0
United Kingdom Pension Plan [Member]
Pension plans in which accumulated benefit obligation exceeded plan assets
United Kingdom pension plan percentage of international pension plans' projected benefit obligations		81.00%

[1] Strategy of equity funds is to invest in diversified funds of global common stocks.

[2] Strategy of bond funds is to invest in diversified funds of fixed income securities of varying geographies and credit quality.

[3] Strategy of alternative funds is to invest in a fund of diversifying investments, including but not limited to reinsurance, commodities, and currencies.

[4] Strategy of real estate funds is to invest in diversified funds of real estate investment trusts and private real estate.

[5] Other investments primarily include investments in insurance contracts, balanced funds, and government bonds.

[6] Represents investments measured at fair value using the Net Asset Value (NAV) per share practical expedient and thus has not been categorized in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the total value of our international pension plans assets.