Consolidated Statements Of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities:
Net income	$ 123	$ 109
Adjustments to reconcile net income to net cash provided by operating activities:
Depletion, depreciation and amortization	221	212
Exploration expenses, including dry holes	7	0
Deferred income taxes	41	44
Gain on disposition of assets, net	(6)	(24)
Accretion of discount on asset retirement obligations	3	3
Discontinued operations	96	35
Interest expense	4	5
Derivative related activity	86	96
Amortization of stock-based compensation	22	17
Other noncash items	8	(4)
Change in operating assets and liabilities, net of effects from acquisitions and dispositions:
Accounts receivable, net	(37)	(42)
Income taxes receivable	5	6
Inventories	(16)	1
Prepaid expenses	(1)	0
Other current assets	(3)	(1)
Accounts payable	(70)	(57)
Interest payable	(26)	(30)
Income taxes payable	9	0
Other current liabilities	0	(10)
Net cash provided by operating activities	466	360
Cash flows from investing activities:
Proceeds from disposition of assets, net of cash sold	86	46
Additions to oil and gas properties	(664)	(697)
Additions to other assets and other property and equipment, net	(48)	(56)
Net cash used in investing activities	(626)	(707)
Cash flows from financing activities:
Borrowings under long-term debt	150	305
Principal payments on long-term debt	(100)	(1,012)
Proceeds from issuance of common stock, net of issuance costs	0	1,281
Distributions to noncontrolling interests	0	(9)
Payments of other liabilities	(1)	0
Exercise of long-term incentive plan stock options	4	1
Purchases of treasury stock	(31)	(19)
Excess tax benefits from share-based payment arrangements	2	1
Net cash provided by financing activities	24	548
Net increase (decrease) in cash and cash equivalents	(136)	201
Cash and cash equivalents, beginning of period	393	229
Cash and cash equivalents, end of period	$ 257	$ 430