Oil and Natural Gas Property Transactions - Narrative (Details) MMcf in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) a well MMcf	Dec. 31, 2016 USD ($) a well VPP	Dec. 31, 2015 USD ($)
Business Acquisition [Line Items]
Proceeds from divestitures of proved and unproved properties	$ 1,249	$ 1,406	$ 189
Impairments of fixed assets and other	421	$ 838	194
Number of VPP Transactions | VPP		4
Corporate VPP [Member]
Business Acquisition [Line Items]
Payments to Acquire Oil and Gas Property		$ 259
JV Marcellus, Barnett, Utica, Eagle Ford, Mid-Continent [Member]
Business Acquisition [Line Items]
Proceeds from Divestiture of Interest in Joint Venture	10	7	33
Noncontrolling Interest, Chesapeake Cleveland Tonkawa Limited Liability Company [Member]
Business Acquisition [Line Items]
Proceeds from divestitures of proved and unproved properties			90
Other Customers [Member]
Business Acquisition [Line Items]
Proceeds from divestitures of proved and unproved properties			$ 66
Haynesville Shale [Member]
Business Acquisition [Line Items]
Proceeds from divestitures of proved and unproved properties	$ 915
Number Of Net Acres | a	119,500
Productive Gas Wells, Number of Wells, Net | well	576
Payments to Acquire Oil and Gas Property		85
Haynesville Shale [Member] | Natural Gas [Member]
Business Acquisition [Line Items]
Proved Developed Reserves (Volume) | MMcf	80
Other Properties [Member]
Business Acquisition [Line Items]
Proceeds from divestitures of proved and unproved properties	$ 350
Barnett Shale [Member]
Business Acquisition [Line Items]
Proceeds from divestitures of proved and unproved properties		$ 218
Number Of Net Acres | a		212,000
Devonian Shale [Member]
Business Acquisition [Line Items]
Proceeds from divestitures of proved and unproved properties		$ 140
Number Of Net Acres | a		1,300,000
Wells | well		5,300
Number of VPP Transactions | VPP		1
Devonian Shale [Member] | Corporate VPP [Member]
Business Acquisition [Line Items]
Payments to Acquire Oil and Gas Property		$ 127
Other Noncore [Member]
Business Acquisition [Line Items]
Proceeds from divestitures of proved and unproved properties		1,048
Other, Barnett Shale Exit Costs,Termination of Gathering Agreement [Member]
Business Acquisition [Line Items]
Loss on Contract Termination		361
Payments for Restructuring		58
Impairments of fixed assets and other		361
Increase (Decrease) in Deferred Charges		58
Other, Barnett Shale Exit Costs, Other Property and Equipment [Member]
Business Acquisition [Line Items]
Impairments of fixed assets and other		284
Exploration and Production Equipment, Buildings and Land, Devonian Shale [Member]
Business Acquisition [Line Items]
Impairments of fixed assets and other		$ 142