CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Current Assets
Cash and cash equivalents	$ 6,008	$ 3,184
Accounts receivable
Allowance for uncollectible accounts	17	14
Customers	834	1,007
Others	820	721
Properties and Equipment
Net properties and equipment	28,516	32,168
Other Assets	2,134	2,226
Goodwill and Other Intangible Assets	5,714	5,904
Accounts payable
Trade	1,626	1,617
Other Long-term Liabilities
Asset retirement obligations	$ 2,717	$ 2,802
Stockholders’ equity
Common stock, par value per share (in usd per share)	$ 0.1	$ 0.10
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	573,900,000	572,000,000
Treasury stock, shares	21,400,000	20,800,000
Variable Interest Entity, Primary Beneficiary [Member]
Current Assets
Cash and cash equivalents	$ 189	$ 359
Accounts receivable
Customers	69	70
Others	6	80
Properties and Equipment
Net properties and equipment	5,348	5,050
Other Assets	597	609
Goodwill and Other Intangible Assets	1,207	1,221
Accounts payable
Trade	176	234
Other Long-term Liabilities
Asset retirement obligations	$ 140	$ 140