Long-Term Debt - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Aug. 08, 2019	Dec. 31, 2018
Long-term Debt
Long-term debt, gross	$ 46,931,000		$ 10,407,000
Unamortized premium, net	724,000		(36,000)
Debt issuance costs	(141,000)		(54,000)
Long-term finance leases	69,000
Current maturities	(31,000)		(116,000)
LONG-TERM DEBT, NET	$ 47,583,000		10,201,000
Senior Notes | 4.100% senior notes due 2021
Long-term Debt
Interest rate	4.10%
Long-term debt, gross			1,249,000
Senior Notes | 3.125% senior notes due 2022
Long-term Debt
Interest rate	3.125%
Long-term debt, gross			813,000
Senior Notes | 2.600% senior notes due 2022
Long-term Debt
Interest rate	2.60%
Long-term debt, gross			400,000
Senior Notes | 2.700% senior notes due 2023
Long-term Debt
Interest rate	2.70%
Long-term debt, gross			1,191,000
Senior Notes | 3.500% senior notes due 2025
Long-term Debt
Interest rate	3.50%
Long-term debt, gross			750,000
Senior Notes | 3.400% senior notes due 2026
Long-term Debt
Interest rate	3.40%
Long-term debt, gross			1,150,000
Senior Notes | 3.000% senior notes due 2027
Long-term Debt
Interest rate	3.00%
Long-term debt, gross			750,000
Senior Notes | 7.200% senior debentures due 2028
Long-term Debt
Interest rate	7.20%
Long-term debt, gross			82,000
Senior Notes | 8.450% senior debentures due 2029
Long-term Debt
Interest rate	8.45%
Long-term debt, gross			116,000
Senior Notes | Zero Coupon senior notes due 2036
Long-term Debt
Interest rate	5.24%
Senior Notes | 4.625% senior notes due 2045
Long-term Debt
Interest rate	4.625%
Long-term debt, gross			750,000
Senior Notes | 4.400% senior notes due 2046
Long-term Debt
Interest rate	4.40%
Long-term debt, gross			1,200,000
Senior Notes | 4.100% senior notes due 2047
Long-term Debt
Interest rate	4.10%
Long-term debt, gross			750,000
Senior Notes | 4.200% senior notes due 2048
Long-term Debt
Interest rate	4.20%
Long-term debt, gross			1,000,000
Senior Notes | 9.250% senior debentures due 2019
Long-term Debt
Interest rate	9.25%
Long-term debt, gross			$ 116,000
Variable Rate Bonds | Variable rate bonds due 2030 (1.9% as of December 31, 2018)
Long-term Debt
Effective interest rate			1.90%
Long-term debt, gross			$ 68,000
Medium-term Notes | 8.750% medium-term notes due 2023
Long-term Debt
Interest rate	8.75%
Long-term debt, gross			22,000
Occidental
Long-term Debt
Long-term debt, gross	$ 39,151,000
Unamortized premium, net	859,000
Debt issuance costs	(133,000)
Long-term finance leases	69,000
Long-term debt	39,946,000
LONG-TERM DEBT, NET	$ 39,946,000		10,201,000
Occidental | Senior Notes | 4.850% senior notes due 2021
Long-term Debt
Interest rate	4.85%
Long-term debt, gross	$ 677,000
Occidental | Senior Notes | 2.600% senior notes due 2021
Long-term Debt
Interest rate	2.60%
Long-term debt, gross	$ 1,500,000
Occidental | Senior Notes | 4.100% senior notes due 2021
Long-term Debt
Interest rate	4.10%
Long-term debt, gross	$ 1,249,000
Occidental | Senior Notes | 2.700% senior notes due 2022
Long-term Debt
Interest rate	2.70%
Long-term debt, gross	$ 2,000,000
Occidental | Senior Notes | 3.125% senior notes due 2022
Long-term Debt
Interest rate	3.125%
Long-term debt, gross	$ 814,000
Occidental | Senior Notes | 2.600% senior notes due 2022
Long-term Debt
Interest rate	2.60%
Long-term debt, gross	$ 400,000
Occidental | Senior Notes | 2.700% senior notes due 2023
Long-term Debt
Interest rate	2.70%
Long-term debt, gross	$ 1,191,000
Occidental | Senior Notes | 2.900% senior notes due 2024
Long-term Debt
Interest rate	2.90%
Long-term debt, gross	$ 3,000,000
Occidental | Senior Notes | 6.950% senior notes due 2024
Long-term Debt
Interest rate	6.95%
Long-term debt, gross	$ 650,000
Occidental | Senior Notes | 3.450% senior notes due 2024
Long-term Debt
Interest rate	3.45%
Long-term debt, gross	$ 248,000
Occidental | Senior Notes | 3.500% senior notes due 2025
Long-term Debt
Interest rate	3.50%
Long-term debt, gross	$ 750,000
Occidental | Senior Notes | 5.550% senior notes due 2026
Long-term Debt
Interest rate	5.55%
Long-term debt, gross	$ 1,100,000
Occidental | Senior Notes | 3.200% senior notes due 2026
Long-term Debt
Interest rate	3.20%
Long-term debt, gross	$ 1,000,000
Occidental | Senior Notes | 3.400% senior notes due 2026
Long-term Debt
Interest rate	3.40%
Long-term debt, gross	$ 1,150,000
Occidental | Senior Notes | 7.500% debentures due 2026
Long-term Debt
Interest rate	7.50%
Occidental | Senior Notes | 3.000% senior notes due 2027
Long-term Debt
Interest rate	3.00%
Long-term debt, gross	$ 750,000
Occidental | Senior Notes | 7.125% debentures due 2027
Long-term Debt
Interest rate	7.125%
Occidental | Senior Notes | 7.000% debentures due 2027
Long-term Debt
Interest rate	7.00%
Occidental | Senior Notes | 6.625% debentures due 2028
Long-term Debt
Interest rate	6.625%
Occidental | Senior Notes | 7.150% debentures due 2028
Long-term Debt
Interest rate	7.15%
Occidental | Senior Notes | 7.200% senior debentures due 2028
Long-term Debt
Interest rate	7.20%
Long-term debt, gross	$ 82,000
Occidental | Senior Notes | 7.200% debentures due 2029
Long-term Debt
Interest rate	7.20%
Occidental | Senior Notes | 7.950% debentures due 2029
Long-term Debt
Interest rate	7.95%
Occidental | Senior Notes | 8.450% senior debentures due 2029
Long-term Debt
Interest rate	8.45%
Long-term debt, gross	$ 116,000
Occidental | Senior Notes | 3.500 senior notes due 2029
Long-term Debt
Interest rate	3.50%
Long-term debt, gross	$ 1,500,000
Occidental | Senior Notes | 7.500% senior notes due 2031
Long-term Debt
Interest rate	7.50%
Long-term debt, gross	$ 900,000
Occidental | Senior Notes | 7.875% senior notes due 2031
Long-term Debt
Interest rate	7.875%
Long-term debt, gross	$ 500,000
Occidental | Senior Notes | 6.450% senior notes due 2036
Long-term Debt
Interest rate	6.45%
Long-term debt, gross	$ 1,750,000
Occidental | Senior Notes | Zero Coupon senior notes due 2036
Long-term Debt
Long-term debt, gross	$ 2,271,000
Occidental | Senior Notes | 4.300% senior notes due 2039
Long-term Debt
Interest rate	4.30%
Long-term debt, gross	$ 750,000
Occidental | Senior Notes | 7.950% senior notes due 2039
Long-term Debt
Interest rate	7.95%
Long-term debt, gross	$ 325,000
Occidental | Senior Notes | 6.200% senior notes due 2040
Long-term Debt
Interest rate	6.20%
Long-term debt, gross	$ 750,000
Occidental | Senior Notes | 4.500% senior notes due 2044
Long-term Debt
Interest rate	4.50%
Long-term debt, gross	$ 625,000
Occidental | Senior Notes | 4.625% senior notes due 2045
Long-term Debt
Interest rate	4.625%
Long-term debt, gross	$ 750,000
Occidental | Senior Notes | 6.600% senior notes due 2046
Long-term Debt
Interest rate	6.60%
Long-term debt, gross	$ 1,100,000
Occidental | Senior Notes | 4.400% senior notes due 2046
Long-term Debt
Interest rate	4.40%
Long-term debt, gross	$ 1,200,000
Occidental | Senior Notes | 4.100% senior notes due 2047
Long-term Debt
Interest rate	4.10%
Long-term debt, gross	$ 750,000
Occidental | Senior Notes | 4.200% senior notes due 2048
Long-term Debt
Interest rate	4.20%
Long-term debt, gross	$ 1,000,000
Occidental | Senior Notes | 4.400% senior notes due 2049
Long-term Debt
Interest rate	4.40%
Long-term debt, gross	$ 750,000
Occidental | Variable Rate Bonds | Variable rate bonds due 2021
Long-term Debt
Effective interest rate	3.137%
Long-term debt, gross	$ 500,000
Occidental | Variable Rate Bonds | Variable rate bonds due 2021
Long-term Debt
Effective interest rate	3.437%
Long-term debt, gross	$ 500,000
Occidental | Variable Rate Bonds | 2-year variable rate Term Loan due 2021
Long-term Debt
Effective interest rate	3.417%
Occidental | Variable Rate Bonds | Variable rate bonds due 2022
Long-term Debt
Effective interest rate	3.637%
Long-term debt, gross	$ 1,500,000
Occidental | Variable Rate Bonds | Variable rate bonds due 2030
Long-term Debt
Effective interest rate	1.785%
Long-term debt, gross	$ 68,000
Occidental | Medium-term Notes | 8.750% medium-term notes due 2023
Long-term Debt
Interest rate	8.75%
Long-term debt, gross	$ 22,000
Occidental | Debentures | 7.500% debentures due 2026
Long-term Debt
Long-term debt, gross	112,000
Occidental | Debentures | 7.125% debentures due 2027
Long-term Debt
Long-term debt, gross	150,000
Occidental | Debentures | 7.000% debentures due 2027
Long-term Debt
Long-term debt, gross	48,000
Occidental | Debentures | 6.625% debentures due 2028
Long-term Debt
Long-term debt, gross	14,000
Occidental | Debentures | 7.150% debentures due 2028
Long-term Debt
Long-term debt, gross	235,000
Occidental | Debentures | 7.200% debentures due 2029
Long-term Debt
Long-term debt, gross	135,000
Occidental | Debentures | 7.950% debentures due 2029
Long-term Debt
Long-term debt, gross	$ 116,000
Occidental | Debentures | 7.730% debentures due 2096
Long-term Debt
Interest rate	7.73%
Long-term debt, gross	$ 60,000
Occidental | Debentures | 7.500% debentures due 2096
Long-term Debt
Interest rate	7.50%
Long-term debt, gross	$ 78,000
Occidental | Debentures | 7.250% debentures due 2096
Long-term Debt
Interest rate	7.25%
Long-term debt, gross	$ 49,000
Occidental | Debentures | 7.250% senior notes due 2025
Long-term Debt
Interest rate	7.25%
Long-term debt, gross	$ 310
Occidental | The Term Loans | 2-year variable rate Term Loan due 2021
Long-term Debt
Effective interest rate	3.417%
Debt instrument term	2 years
Long-term debt, gross	$ 3,966,000
WES
Long-term Debt
Long-term debt, gross	7,780,000
Unamortized discount net	(135,000)
Debt issuance costs	(8,000)
Long-term debt		$ 4,600,000
LONG-TERM DEBT, NET	7,637,000		$ 0
WES | Senior Notes
Long-term Debt
Long-term debt	$ 4,600,000
WES | Senior Notes | 5.375% senior notes due 2021
Long-term Debt
Interest rate	5.375%
Long-term debt, gross	$ 500,000
WES | Senior Notes | 4.000% senior notes due 2022
Long-term Debt
Interest rate	4.00%
Long-term debt, gross	$ 670,000
WES | Senior Notes | 3.950% senior notes due 2025
Long-term Debt
Interest rate	3.95%
Long-term debt, gross	$ 500,000
WES | Senior Notes | 4.650% senior notes due 2026
Long-term Debt
Interest rate	4.65%
Long-term debt, gross	$ 500,000
WES | Senior Notes | 4.500% senior notes due 2028
Long-term Debt
Interest rate	4.50%
Long-term debt, gross	$ 400,000
WES | Senior Notes | 4.750% senior notes due 2028
Long-term Debt
Interest rate	4.75%
Long-term debt, gross	$ 400,000
WES | Senior Notes | 5.450% senior notes due 2044
Long-term Debt
Interest rate	5.45%
Long-term debt, gross	$ 600,000
WES | Senior Notes | 5.300% senior notes due 2048
Long-term Debt
Interest rate	5.30%
Long-term debt, gross	$ 700,000
WES | Senior Notes | 5.500% senior notes due 2048
Long-term Debt
Interest rate	5.50%
Long-term debt, gross	$ 350,000
WES | The Term Loans
Long-term Debt
Long-term debt	$ 3,000,000
WES | The Term Loans | Term Loan Facility
Long-term Debt
Effective interest rate	3.42%
Long-term debt, gross	$ 3,000,000
WES | Line of Credit | Revolving Credit Facility
Long-term Debt
Effective interest rate	3.34%
Long-term debt, gross	$ 160,000