CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
OPERATING REVENUES	$ 4,382	$ 4,554	$ 13,181	$ 13,424
OPERATING EXPENSES
Cost of services and products (exclusive of depreciation and amortization)	1,996	1,993	5,845	5,863
Selling, general and administrative	796	857	2,439	2,571
Depreciation and amortization	995	1,048	2,958	3,136
Total operating expenses	3,787	3,898	11,242	11,570
OPERATING INCOME	595	656	1,939	1,854
OTHER (EXPENSE) INCOME
Interest expense	(327)	(329)	(998)	(984)
Other (expense) income, net	(19)	2	5	16
Total other expense, net	(346)	(327)	(993)	(968)
INCOME BEFORE INCOME TAX EXPENSE	249	329	946	886
Income tax expense	97	124	362	346
NET INCOME	$ 152	$ 205	$ 584	$ 540
BASIC AND DILUTED EARNINGS PER COMMON SHARE
BASIC (in dollars per share)	$ 0.28	$ 0.37	$ 1.08	$ 0.97
DILUTED (in dollars per share)	0.28	0.37	1.08	0.97
DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.54	$ 0.54	$ 1.62	$ 1.62
WEIGHTED-AVERAGE COMMON SHARES OUTSTANDING
BASIC (in shares)	539,806	554,897	539,411	558,502
DILUTED (in shares)	540,917	555,156	540,493	559,293