Condensed Consolidating Statements Of Cash Flows (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Net Cash Provided By Operating Activities	$ 4,614	$ 2,837	$ 5,903
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions of proved and unproved properties	(6,636)	(12,091)	(12,441)
Proceeds from divestitures of proved and unproved properties	3,467	5,884	7,651
Additions to other property and equipment	(972)	(2,651)	(2,009)
Other investing activities	1,174	3,874	987
Net Cash Used In Investing Activities	(2,967)	(4,984)	(5,812)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from credit facilities borrowings	7,669	20,318	15,509
Payments on credit facilities borrowings	(7,682)	(21,650)	(17,466)
Proceeds from issuance of senior notes, net of discount and offering costs	2,274	1,263	1,614
Proceeds from issuance of term loans, net of discount and offering costs	0	5,722	0
Repayments of Long-term Debt	(2,141)	(4,000)	(2,015)
Proceeds from sales of noncontrolling interests	6	1,077	1,348
Other financing activities	(1,223)	(647)	1,168
Intercompany advances, net	0	0	0
Net Cash Provided By (Used In) Financing Activities	(1,097)	2,083	158
Net increase (decrease) in cash and cash equivalents	550	(64)	249
Cash and cash equivalents, beginning of period	287	351	102
Cash and cash equivalents, end of period	837	287	351
Parent
Condensed Financial Statements, Captions [Line Items]
Net Cash Provided By Operating Activities	0	0	0
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions of proved and unproved properties	0	0	0
Proceeds from divestitures of proved and unproved properties	0	0	0
Additions to other property and equipment	0	0	0
Other investing activities	0	0	0
Net Cash Used In Investing Activities	0	0	0
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from credit facilities borrowings	0	0	0
Payments on credit facilities borrowings	0	0	0
Proceeds from issuance of senior notes, net of discount and offering costs	2,274	1,263	977
Proceeds from issuance of term loans, net of discount and offering costs		5,722
Repayments of Long-term Debt	(2,141)	(4,000)	(2,015)
Proceeds from sales of noncontrolling interests	0	0	0
Other financing activities	1,819	(477)	(494)
Intercompany advances, net	(1,381)	(2,282)	1,533
Net Cash Provided By (Used In) Financing Activities	571	226	1
Net increase (decrease) in cash and cash equivalents	571	226	1
Cash and cash equivalents, beginning of period	228	2	1
Cash and cash equivalents, end of period	799	228	2
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net Cash Provided By Operating Activities	4,115	3,662	5,868
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions of proved and unproved properties	(6,226)	(11,099)	(10,420)
Proceeds from divestitures of proved and unproved properties	3,414	5,583	7,651
Additions to other property and equipment	(581)	(855)	(520)
Other investing activities	117	4,705	(348)
Net Cash Used In Investing Activities	(3,276)	(1,666)	(3,637)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from credit facilities borrowings	6,452	18,336	14,005
Payments on credit facilities borrowings	(6,452)	(20,056)	(15,898)
Proceeds from issuance of senior notes, net of discount and offering costs	0	0	0
Proceeds from issuance of term loans, net of discount and offering costs		0
Repayments of Long-term Debt	0	0	0
Proceeds from sales of noncontrolling interests	0	0	0
Other financing activities	(2,809)	(153)	1,413
Intercompany advances, net	1,970	(123)	(1,751)
Net Cash Provided By (Used In) Financing Activities	(839)	(1,996)	(2,231)
Net increase (decrease) in cash and cash equivalents	0	0	0
Cash and cash equivalents, beginning of period	0	0	0
Cash and cash equivalents, end of period	0	0	0
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net Cash Provided By Operating Activities	542	431	438
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions of proved and unproved properties	(410)	(992)	(2,021)
Proceeds from divestitures of proved and unproved properties	53	301	0
Additions to other property and equipment	(391)	(1,796)	(1,489)
Other investing activities	765	2,133	719
Net Cash Used In Investing Activities	17	(354)	(2,791)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from credit facilities borrowings	1,217	1,982	1,504
Payments on credit facilities borrowings	(1,230)	(1,594)	(1,568)
Proceeds from issuance of senior notes, net of discount and offering costs	0	0	637
Proceeds from issuance of term loans, net of discount and offering costs		0
Repayments of Long-term Debt	0	0	0
Proceeds from sales of noncontrolling interests	6	1,077	1,348
Other financing activities	17	(4,237)	462
Intercompany advances, net	(589)	2,405	218
Net Cash Provided By (Used In) Financing Activities	(579)	(367)	2,601
Net increase (decrease) in cash and cash equivalents	(20)	(290)	248
Cash and cash equivalents, beginning of period	59	349	101
Cash and cash equivalents, end of period	39	59	349
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net Cash Provided By Operating Activities	(43)	(1,256)	(403)
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions of proved and unproved properties	0	0	0
Proceeds from divestitures of proved and unproved properties	0	0	0
Additions to other property and equipment	0	0	0
Other investing activities	292	(2,964)	616
Net Cash Used In Investing Activities	292	(2,964)	616
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from credit facilities borrowings	0	0	0
Payments on credit facilities borrowings	0	0	0
Proceeds from issuance of senior notes, net of discount and offering costs	0	0	0
Proceeds from issuance of term loans, net of discount and offering costs		0
Repayments of Long-term Debt	0	0	0
Proceeds from sales of noncontrolling interests	0	0	0
Other financing activities	(250)	4,220	(213)
Intercompany advances, net	0	0	0
Net Cash Provided By (Used In) Financing Activities	(250)	4,220	(213)
Net increase (decrease) in cash and cash equivalents	(1)	0	0
Cash and cash equivalents, beginning of period	0	0	0
Cash and cash equivalents, end of period	$ (1)	$ 0	$ 0