Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating activities
Net income	$ 366	$ 138	$ 1,070	$ 436
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	1,568	1,157	4,695	3,319
Stock-based compensation expense	59	42	171	153
Deferred income tax expense	219	134	623	82
Bad debt expense	118	172	358	384
Losses from sales of receivables	59	26	157	139
Deferred rent expense	32	43	97	131
Gains on disposal of spectrum licenses	(199)	(1)	(835)	(24)
Changes in operating assets and liabilities
Accounts receivable	(155)	(48)	(462)	(156)
Equipment installment plan receivables	104	229	556	(350)
Inventories	301	(915)	(497)	(973)
Deferred purchase price from sales of receivables	(16)	(34)	(199)	(46)
Other current and long-term assets	(98)	(184)	31	(58)
Accounts payable and accrued liabilities	(731)	582	(1,568)	36
Other current and long-term liabilities	112	92	326	2
Other, net	1	98	10	106
Net cash provided by operating activities	1,740	1,531	4,533	3,181
Investing activities
Purchases of property and equipment	(1,159)	(1,120)	(3,843)	(3,293)
Purchases of spectrum licenses and other intangible assets, including deposits	(705)	(94)	(3,544)	(1,938)
Sales of short-term investments	0	0	2,998	0
Other, net	5	5	3	(7)
Net cash used in investing activities	(1,859)	(1,209)	(4,386)	(5,238)
Financing activities
Proceeds from issuance of long-term debt	0	0	997	0
Repayments of capital lease obligations	(54)	(13)	(133)	(24)
Repayments of short-term debt for purchases of inventory, property and equipment, net	0	(315)	(150)	(563)
Repayments of long-term debt	(5)	0	(15)	0
Tax withholdings on share-based awards	(3)	(2)	(52)	(100)
Dividends on preferred stock	(13)	(13)	(41)	(41)
Other, net	8	12	17	103
Net cash provided by (used in) financing activities	(67)	(331)	623	(625)
Change in cash and cash equivalents	(186)	(9)	770	(2,682)
Cash and cash equivalents
Beginning of period	5,538	2,642	4,582	5,315
End of period	5,352	2,633	5,352	2,633
Supplemental disclosure of cash flow information
Interest payments, net of amounts capitalized	478	348	1,292	969
Income tax payments	4	8	23	41
Changes in accounts payable for purchases of property and equipment	(79)	267	(307)	94
Leased devices transferred from inventory to property and equipment	234	854	1,175	854
Returned leased devices transferred from property and equipment to inventory	(186)	(32)	(422)	(32)
Issuance of short-term debt for financing of property and equipment	0	0	150	500
Assets acquired under capital lease obligations	$ 384	$ 119	$ 679	$ 309