Commitments, Contingencies and Guarantees (Obligations) (Details) $ in Millions	Dec. 31, 2018 USD ($)
Guarantee obligations	$ 240
Contractual obligation payments due	12,969	[1]
Total commitments and contingencies	13,209	[1]
Amended PCC Plan [Member]
Contractual obligation payments due	185
Purchase Obligations [Member]
Contractual obligation payments due	339	[2]
Capital Expenditure Obligations [Member]
Contractual obligation payments due	412	[3]
Total Debt [Member]
Contractual obligation payments due	5,642	[4]
Interest on Long-term Debt [Member]
Contractual obligation payments due	5,117	[5]
Capital Leases and Financing Obligations [Member]
Contractual obligation payments due	393
Imputed Interest on Capital Leases and Financing Obligations [Member]
Contractual obligation payments due	205
Minimum Rental Commitments [Member]
Contractual obligation payments due	581
Uncertain Tax Positions [Member]
Contractual obligation payments due	95	[1]
Less Than 1 Year [Member]
Guarantee obligations	98
Contractual obligation payments due	1,013	[1]
Total commitments and contingencies	1,111	[1]
Less Than 1 Year [Member] | Amended PCC Plan [Member]
Contractual obligation payments due	50
Less Than 1 Year [Member] | Purchase Obligations [Member]
Contractual obligation payments due	214	[2]
Less Than 1 Year [Member] | Capital Expenditure Obligations [Member]
Contractual obligation payments due	412	[3]
Less Than 1 Year [Member] | Interest on Long-term Debt [Member]
Contractual obligation payments due	231	[5]
Less Than 1 Year [Member] | Capital Leases and Financing Obligations [Member]
Contractual obligation payments due	4
Less Than 1 Year [Member] | Imputed Interest on Capital Leases and Financing Obligations [Member]
Contractual obligation payments due	20
Less Than 1 Year [Member] | Minimum Rental Commitments [Member]
Contractual obligation payments due	82
1 to 3 Years [Member]
Guarantee obligations	12
Contractual obligation payments due	1,135	[1]
Total commitments and contingencies	1,147	[1]
1 to 3 Years [Member] | Amended PCC Plan [Member]
Contractual obligation payments due	85
1 to 3 Years [Member] | Purchase Obligations [Member]
Contractual obligation payments due	56	[2]
1 to 3 Years [Member] | Total Debt [Member]
Contractual obligation payments due	362	[4]
1 to 3 Years [Member] | Interest on Long-term Debt [Member]
Contractual obligation payments due	450	[5]
1 to 3 Years [Member] | Capital Leases and Financing Obligations [Member]
Contractual obligation payments due	11
1 to 3 Years [Member] | Imputed Interest on Capital Leases and Financing Obligations [Member]
Contractual obligation payments due	38
1 to 3 Years [Member] | Minimum Rental Commitments [Member]
Contractual obligation payments due	133
3 to 5 Years [Member]
Guarantee obligations	2
Contractual obligation payments due	1,436	[1]
Total commitments and contingencies	1,438	[1]
3 to 5 Years [Member] | Amended PCC Plan [Member]
Contractual obligation payments due	50
3 to 5 Years [Member] | Purchase Obligations [Member]
Contractual obligation payments due	28	[2]
3 to 5 Years [Member] | Total Debt [Member]
Contractual obligation payments due	670	[4]
3 to 5 Years [Member] | Interest on Long-term Debt [Member]
Contractual obligation payments due	408	[5]
3 to 5 Years [Member] | Capital Leases and Financing Obligations [Member]
Contractual obligation payments due	132
3 to 5 Years [Member] | Imputed Interest on Capital Leases and Financing Obligations [Member]
Contractual obligation payments due	37
3 to 5 Years [Member] | Minimum Rental Commitments [Member]
Contractual obligation payments due	111
More Than 5 Years [Member]
Guarantee obligations	128
Contractual obligation payments due	9,290	[1]
Total commitments and contingencies	9,418	[1]
More Than 5 Years [Member] | Purchase Obligations [Member]
Contractual obligation payments due	41	[2]
More Than 5 Years [Member] | Total Debt [Member]
Contractual obligation payments due	4,610	[4]
More Than 5 Years [Member] | Interest on Long-term Debt [Member]
Contractual obligation payments due	4,028	[5]
More Than 5 Years [Member] | Capital Leases and Financing Obligations [Member]
Contractual obligation payments due	246
More Than 5 Years [Member] | Imputed Interest on Capital Leases and Financing Obligations [Member]
Contractual obligation payments due	110
More Than 5 Years [Member] | Minimum Rental Commitments [Member]
Contractual obligation payments due	255
Performance Bonds and Guarantees [Member]
Guarantee obligations	152
Performance Bonds and Guarantees [Member] | Less Than 1 Year [Member]
Guarantee obligations	23
Performance Bonds and Guarantees [Member] | 1 to 3 Years [Member]
Guarantee obligations	4
Performance Bonds and Guarantees [Member] | 3 to 5 Years [Member]
Guarantee obligations	2
Performance Bonds and Guarantees [Member] | More Than 5 Years [Member]
Guarantee obligations	123
Stand-by Letter of Credit [Member]
Guarantee obligations	84	[6]
Stand-by Letter of Credit [Member] | Less Than 1 Year [Member]
Guarantee obligations	71	[6]
Stand-by Letter of Credit [Member] | 1 to 3 Years [Member]
Guarantee obligations	8	[6]
Stand-by Letter of Credit [Member] | More Than 5 Years [Member]
Guarantee obligations	5	[6]
Credit Facility to Equity Company [Member]
Guarantee obligations	4
Credit Facility to Equity Company [Member] | Less Than 1 Year [Member]
Guarantee obligations	4
Other Current Liabilities [Member] | Stand-by Letter of Credit [Member]
Guarantee obligations	39
Uncertain Tax Positions [Member]
Contractual obligation payments due	$ 95

[1] At December 31, 2018, $95 million was included on our balance sheet related to uncertain tax positions.

[2] Purchase obligations are enforceable and legally binding obligations which primarily consist of raw material and energy-related take-or-pay contracts.

[3] Capital expenditure obligations primarily reflect amounts associated with our capital expansion activities.

[4] Total debt above is stated at maturity value, and excludes interest rate swap gains/losses and bond discounts.

[5] The estimate of interest payments assumes interest is paid through the date of maturity or expiration of the related debt, based upon stated rates in the respective debt instruments.

[6] At December 31, 2018, $39 million of the $84 million was included in other accrued liabilities on our consolidated balance sheets.