Employee Benefit Plans, Fair Value of Pension Plan Assets (Details) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity Securities [Member]
Employee Benefit Plans (Textual)
Percentage of equity securities in target allocations for plan assets		70.00%
Debt Securities [Member]
Employee Benefit Plans (Textual)
Percentage of equity securities in target allocations for plan assets		30.00%
Pension Plans [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[1]	$ 2,709	$ 2,236	$ 2,428
Pension Plans [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		1,145	909
Pension Plans [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		1,564	1,327
Pension Plans [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | US Companies [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[2]	622	497
Pension Plans [Member] | US Companies [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[2]	622	497
Pension Plans [Member] | US Companies [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[2]	0	0
Pension Plans [Member] | US Companies [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[2]	0	0
Pension Plans [Member] | International Companies [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		206	160
Pension Plans [Member] | International Companies [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		205	159
Pension Plans [Member] | International Companies [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		1	1
Pension Plans [Member] | International Companies [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Preferred Stock [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		4	4
Pension Plans [Member] | Preferred Stock [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		4	4
Pension Plans [Member] | Preferred Stock [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Preferred Stock [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | International Growth [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		123	97
Pension Plans [Member] | International Growth [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		123	97
Pension Plans [Member] | International Growth [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | International Growth [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Index Funds [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		90	76
Pension Plans [Member] | Index Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		90	76
Pension Plans [Member] | Index Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Index Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Corporate Debt Instruments [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[2]	293	284
Pension Plans [Member] | Corporate Debt Instruments [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[2]	0	0
Pension Plans [Member] | Corporate Debt Instruments [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[2]	293	284
Pension Plans [Member] | Corporate Debt Instruments [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[2]	0	0
Pension Plans [Member] | US Treasury Securities [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		53	45
Pension Plans [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		53	45
Pension Plans [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Other Government Securities [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		148	138
Pension Plans [Member] | Other Government Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Other Government Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		148	138
Pension Plans [Member] | Other Government Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Defined Benefit Plan, Common Collective Trust [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[3]	751	609
Pension Plans [Member] | Defined Benefit Plan, Common Collective Trust [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[3]	0	0
Pension Plans [Member] | Defined Benefit Plan, Common Collective Trust [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[3]	751	609
Pension Plans [Member] | Defined Benefit Plan, Common Collective Trust [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[3]	$ 0	$ 0
Pension Plans [Member] | Common Collective Trusts - Equity Securities [Member]
Employee Benefit Plans (Textual)
Defined benefit plan, actual plan asset allocations		75.00%	70.00%
Pension Plans [Member] | Common Collective Trusts - Debt Securities [Member]
Employee Benefit Plans (Textual)
Defined benefit plan, actual plan asset allocations		25.00%	30.00%
Pension Plans [Member] | Pooled Separate Accounts [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		$ 250	$ 190
Pension Plans [Member] | Pooled Separate Accounts [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Pooled Separate Accounts [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		250	190
Pension Plans [Member] | Pooled Separate Accounts [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Private Funds [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		104	87
Pension Plans [Member] | Private Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Private Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		104	87
Pension Plans [Member] | Private Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Insurance Contract [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		17	18
Pension Plans [Member] | Insurance Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Insurance Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		17	18
Pension Plans [Member] | Insurance Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Interest and Dividends Receivable [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		5	5
Pension Plans [Member] | Interest and Dividends Receivable [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		5	5
Pension Plans [Member] | Interest and Dividends Receivable [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Interest and Dividends Receivable [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Cash and Cash Equivalents [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		59	40
Pension Plans [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		59	40
Pension Plans [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Securities Transactions Payable, Net [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		(16)	(14)
Pension Plans [Member] | Securities Transactions Payable, Net [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		(16)	(14)
Pension Plans [Member] | Securities Transactions Payable, Net [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Pension Plans [Member] | Securities Transactions Payable, Net [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		$ 0	$ 0

[1] Plan assets include only the assets associated with pension plans subject to legal minimum funding standards. Plan assets associated with U.S. nonqualified pension plans are not included here because they are not protected from our creditors and therefore cannot be reflected as a reduction from our obligations under the pension plans. As a result, the reconciliation of funded status does not reflect the effect of plan assets that exist for all of our defined benefit plans. See Note 19 for the assets associated with certain U.S. nonqualified pension plans.

[2] This class of securities is held in a wide range of industrial sectors.

[3] This class includes primarily investments in approximately 75 percent equities and 25 percent bonds as of December 31, 2019. As of December 31, 2018, this class included primarily investments in approximately 70 percent equities and 30 percent bonds.