Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income	$ 289	$ 350
Adjustments to reconcile net income to net cash provided by operating activities:
Depletion, depreciation and amortization	434	421
Impairment of inventory and other property and equipment	0	32
Exploration expenses, including dry holes	2	1
Deferred income taxes	76	103
Loss on disposition of assets, net	0	9
Accretion of discount on asset retirement obligations	2	3
Interest expense	5	1
Derivative related activity	(412)	17
Amortization of stock-based compensation	16	24
Investment in affiliate valuation adjustment	(145)	174
South Texas contingent consideration valuation adjustment	63	0
South Texas deficiency fee obligation	69	0
Other	31	62
Change in operating assets and liabilities:
Accounts receivable	479	(69)
Inventories	16	(36)
Other assets	21	(15)
Accounts payable	(284)	(74)
Interest payable	(35)	(29)
Other liabilities	(92)	(22)
Net cash provided by operating activities	825	604
Cash flows from investing activities:
Proceeds from disposition of assets, net of cash sold	1	6
Proceeds from investments	0	112
Additions to oil and gas properties	(639)	(741)
Additions to other assets and other property and equipment	(43)	(72)
Net cash used in investing activities	(681)	(695)
Cash flows from financing activities:
Borrowing under credit facility	800	0
Principal payments on long-term debt	(450)	0
Payments of other liabilities	(146)	(1)
Purchases of treasury stock	(122)	(222)
Dividends paid	(73)	0
Net cash provided by (used in) financing activities	9	(223)
Net increase (decrease) in cash, cash equivalents and restricted cash	153	(314)
Cash, cash equivalents and restricted cash, beginning of period	705	825
Cash, cash equivalents and restricted cash, end of period	$ 858	$ 511