CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
OPERATING ACTIVITIES
Net income	$ 432	$ 335
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,963	2,088
Impairment of assets	1	8
Deferred income taxes	21	53
Provision for uncollectible accounts	96	84
Net long-term debt issuance costs and premium amortization	0	(3)
Share-based compensation	40	38
Changes in current assets and liabilities:
Accounts receivable	(125)	(51)
Accounts payable	74	(112)
Accrued income and other taxes	208	120
Other current assets and liabilities, net	(64)	(50)
Retirement benefits	(28)	(19)
Changes in other noncurrent assets and liabilities, net	(35)	(11)
Other, net	18	1
Net cash provided by operating activities	2,601	2,481
INVESTING ACTIVITIES
Payments for property, plant and equipment and capitalized software	(1,264)	(1,272)
Cash paid for acquisitions	(24)	(4)
Proceeds from sale of property	11	26
Other, net	(2)	(8)
Net cash used in investing activities	(1,279)	(1,258)
FINANCING ACTIVITIES
Net proceeds from issuance of long-term debt	1,215	594
Payments of long-term debt	(1,464)	(506)
Net payments on credit facility and revolving line of credit	(410)	(405)
Dividends paid	(586)	(609)
Net proceeds from issuance of common stock	3	9
Repurchase of common stock and shares withheld to satisfy tax withholdings	(15)	(277)
Other, net	0	(2)
Net cash used in financing activities	(1,257)	(1,196)
Net increase in cash and cash equivalents	65	27
Cash and cash equivalents at beginning of period	126	128
Cash and cash equivalents at end of period	191	155
Supplemental cash flow information:
Income taxes paid, net	(21)	(41)
Interest paid (net of capitalized interest of $24 and $29)	$ (660)	$ (654)