CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
OPERATING REVENUES	$ 4,398	$ 4,419	$ 8,799	$ 8,870
OPERATING EXPENSES
Cost of services and products (exclusive of depreciation and amortization)	1,949	1,959	3,849	3,870
Selling, general and administrative	812	863	1,643	1,714
Depreciation and amortization	987	1,048	1,963	2,088
Total operating expenses	3,748	3,870	7,455	7,672
OPERATING INCOME	650	549	1,344	1,198
OTHER (EXPENSE) INCOME
Interest expense	(340)	(327)	(671)	(655)
Other income, net	7	12	24	14
Total other expense, net	(333)	(315)	(647)	(641)
INCOME BEFORE INCOME TAX EXPENSE	317	234	697	557
Income tax expense	121	91	265	222
Net income	$ 196	$ 143	$ 432	$ 335
BASIC AND DILUTED EARNINGS PER COMMON SHARE
BASIC (in dollars per share)	$ 0.36	$ 0.26	$ 0.80	$ 0.60
DILUTED (in dollars per share)	0.36	0.26	0.80	0.60
DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.54	$ 0.54	$ 1.08	$ 1.08
WEIGHTED-AVERAGE COMMON SHARES OUTSTANDING
BASIC (in shares)	539,627	558,640	539,213	560,304
DILUTED (in shares)	540,375	559,220	540,281	561,362