CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
OPERATING REVENUES	$ 4,090	$ 4,398	$ 8,299	$ 8,799
OPERATING EXPENSES
Cost of services and products (exclusive of depreciation and amortization)	1,890	1,949	3,778	3,849
Selling, general and administrative	884	815	1,694	1,652
Depreciation and amortization	949	987	1,829	1,963
Total operating expenses	3,723	3,751	7,301	7,464
OPERATING INCOME	367	647	998	1,335
OTHER (EXPENSE) INCOME
Interest expense	(320)	(340)	(638)	(671)
Other (expense) income, net	(7)	10	(13)	33
Total other expense, net	(327)	(330)	(651)	(638)
INCOME BEFORE INCOME TAX EXPENSE	40	317	347	697
Income tax expense	23	121	167	265
NET INCOME	$ 17	$ 196	$ 180	$ 432
BASIC AND DILUTED EARNINGS PER COMMON SHARE
BASIC (per share)	$ 0.03	$ 0.36	$ 0.33	$ 0.80
DILUTED (per share)	0.03	0.36	0.33	0.80
DIVIDENDS DECLARED PER COMMON SHARE	$ 0.54	$ 0.54	$ 1.08	$ 1.08
WEIGHTED-AVERAGE COMMON SHARES OUTSTANDING
BASIC (in shares)	541,361	539,627	540,909	539,213
DILUTED (in shares)	542,151	540,375	541,836	540,281