Consolidated Statements Of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income	$ 350	$ 178
Adjustments to reconcile net income to net cash provided by operating activities:
Depletion, depreciation and amortization	421	357
Impairment of inventory and other property and equipment	32	0
Exploration expenses, including dry holes	1	5
Deferred income taxes	103	50
(Gain) loss on disposition of assets, net	9	(4)
Accretion of discount on asset retirement obligations	3	4
Interest expense	1	1
Derivative related activity	17	136
Amortization of stock-based compensation	24	17
Investment in affiliate fair value adjustment	174	0
Other	62	22
Change in operating assets and liabilities:
Accounts receivable	(69)	(181)
Inventories	(36)	(6)
Investments	0	3
Other current assets	(15)	(3)
Accounts payable	(74)	(9)
Interest payable	(29)	(21)
Income taxes payable	0	1
Other current liabilities	(22)	5
Net cash provided by operating activities	604	555
Cash flows from investing activities:
Proceeds from disposition of assets, net of cash sold	6	4
Proceeds from investments	112	554
Purchase of investments	0	(94)
Additions to oil and gas properties	(741)	(818)
Additions to other assets and other property and equipment	(72)	(51)
Net cash used in investing activities	(695)	(405)
Cash flows from financing activities:
Purchase of treasury stock	222	45
Payments of other liabilities	(1)	0
Net cash used in financing activities	(223)	(45)
Net increase (decrease) in cash and cash equivalents	(314)	105
Cash and cash equivalents, beginning of period	825	896
Cash and cash equivalents, end of period	$ 511	$ 1,001