CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
OPERATING REVENUES	$ 4,034	$ 4,382	$ 12,333	$ 13,181
OPERATING EXPENSES
Cost of services and products (exclusive of depreciation and amortization)	1,927	1,996	5,705	5,845
Selling, general and administrative	710	798	2,404	2,450
Depreciation and amortization	910	995	2,739	2,958
Total operating expenses	3,547	3,789	10,848	11,253
OPERATING INCOME	487	593	1,485	1,928
OTHER (EXPENSE) INCOME
Interest expense	(362)	(327)	(1,000)	(998)
Other income (expense), net	14	(17)	1	16
Total other expense, net	(348)	(344)	(999)	(982)
INCOME BEFORE INCOME TAX EXPENSE	139	249	486	946
Income tax expense	47	97	214	362
NET INCOME	$ 92	$ 152	$ 272	$ 584
BASIC AND DILUTED EARNINGS PER COMMON SHARE
BASIC (per share)	$ 0.17	$ 0.28	$ 0.50	$ 1.08
DILUTED (per share)	0.17	0.28	0.50	1.08
DIVIDENDS DECLARED PER COMMON SHARE	$ 0.54	$ 0.54	$ 1.62	$ 1.62
WEIGHTED-AVERAGE COMMON SHARES OUTSTANDING
BASIC (in shares)	541,521	539,806	541,113	539,411
DILUTED (in shares)	541,963	540,917	541,879	540,493