CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Operating revenues	$ 17,900	$ 18,031	$ 18,095
OPERATING EXPENSES
Cost of services and products (exclusive of depreciation and amortization)	7,778	7,846	7,507
Selling, general and administrative	3,328	3,347	3,502
Depreciation and amortization	4,189	4,428	4,541
Impairment of goodwill (Note 2)	0	0	1,092
Total operating expenses	15,295	15,621	16,642
OPERATING INCOME	2,605	2,410	1,453
OTHER (EXPENSE) INCOME
Interest expense	(1,312)	(1,311)	(1,298)
Net gain on early retirement of debt	0	0	10
Other income, net	23	11	59
Total other expense, net	(1,289)	(1,300)	(1,229)
INCOME BEFORE INCOME TAX EXPENSE	1,316	1,110	224
Income tax expense	438	338	463
NET INCOME (LOSS)	$ 878	$ 772	$ (239)
BASIC AND DILUTED EARNINGS (LOSS) PER COMMON SHARE
Basic earnings (loss) per common share (in dollars per share)	$ 1.58	$ 1.36	$ (0.40)
Diluted earnings (loss) per common share (in dollars per share)	$ 1.58	$ 1.36	$ (0.40)
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING
BASIC (in shares)	554,278	568,435	600,892
DILUTED (in shares)	555,093	569,739	600,892