Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net income (loss)	$ (150)	$ 181
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depletion, depreciation and amortization	850	833
Impairment of inventory and other property and equipment	1	31
Exploration expenses, including dry holes	3	4
Deferred income taxes	(11)	56
(Gain) loss on disposition of assets, net	(6)	498
Loss on early extinguishment of debt	27	0
Accretion of discount on asset retirement obligations	5	5
Interest expense	18	3
Derivative-related activity	52	(20)
Amortization of stock-based compensation	33	62
Investment in affiliate valuation adjustment	(101)	171
South Texas contingent consideration valuation adjustment	64	13
South Texas deficiency fee obligation	69	0
Other	64	76
Change in operating assets and liabilities:
Accounts receivable	468	17
Inventories	34	(58)
Other assets	26	(16)
Accounts payable	(313)	(69)
Interest payable	(27)	0
Other liabilities	(154)	(52)
Net cash provided by operating activities	1,154	1,393
Cash flows from investing activities:
Proceeds from disposition of assets	7	57
Proceeds from investments	0	568
Purchase of investments	(1)	0
Additions to oil and gas properties	(1,034)	(1,510)
Additions to other assets and other property and equipment	(78)	(135)
Net cash used in investing activities	(1,106)	(1,020)
Cash flows from financing activities:
Proceeds from issuance of convertible senior notes	1,323	0
Purchase of derivatives related to issuance of convertible senior notes	(113)	0
Borrowing under credit facility	800	0
Repayment of credit facility	(800)	0
Repayment of senior notes, including tender offer premiums	(1,198)	0
Payments of other liabilities	(154)	(2)
Payments of financing fees, net	(26)	0
Purchases of treasury stock	(172)	(424)
Dividends paid	(164)	(54)
Net cash used in financing activities	(504)	(480)
Net decrease in cash, cash equivalents and restricted cash	(456)	(107)
Cash, cash equivalents and restricted cash, beginning of period	705	825
Cash, cash equivalents and restricted cash, end of period	$ 249	$ 718