Guarantor Financial Information (Condensed Consolidating Statement of Cash Flows Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities
Net cash provided by (used in) operating activities	$ 5,414	$ 4,146	$ 3,545
Investing activities
Purchases of property and equipment	(4,724)	(4,317)	(4,025)
Purchases of spectrum licenses and other intangible assets, including deposits	(1,935)	(2,900)	(381)
Purchases of short-term investments	(2,997)	0	0
Short term affiliate loan receivable, net	0	0	300
Cash and cash equivalents acquired in MetroPCS business combination	0	0	2,144
Investment in subsidiaries	0	0
Other, net	96	(29)	(130)
Net cash provided by (used in) investing activities	(9,560)	(7,246)	(2,092)
Financing activities
Proceeds from capital contribution	0	0
Proceeds from issuance of long-term debt	3,979	2,993	2,494
Repayments of long-term debt and capital lease obligations	(57)	(1,019)	(9)
Proceeds from tower obligations	140	0	0
Repayments of short-term debt for purchases of inventory, property and equipment, net	(564)	(418)	(244)
Intercompany dividend paid	0	0
Proceeds from issuance of preferred stock	0	982	0
Dividends on preferred stock	(55)	0	0
Proceeds from exercise of stock options	47	27	137
Proceeds from issuance of common stock	0	0	1,787
Taxes paid related to net share settlement of stock awards	(156)	(73)	0
Other, net	79	32	(121)
Net cash provided by (used in) financing activities	3,413	2,524	4,044
Change in cash and cash equivalents	(733)	(576)	5,497
Beginning of year	5,315	5,891	394
End of year	4,582	5,315	5,891
Consolidating and Eliminating Adjustments [Member]
Operating activities
Net cash provided by (used in) operating activities	(175)	(100)	0
Investing activities
Purchases of property and equipment	0	0	0
Purchases of spectrum licenses and other intangible assets, including deposits	0	0	0
Purchases of short-term investments	0
Short term affiliate loan receivable, net			0
Cash and cash equivalents acquired in MetroPCS business combination			0
Investment in subsidiaries	1,905	1,700
Other, net	0	0	0
Net cash provided by (used in) investing activities	1,905	1,700	0
Financing activities
Proceeds from capital contribution	(1,905)	(1,700)
Proceeds from issuance of long-term debt	0	0	0
Repayments of long-term debt and capital lease obligations	0	0	0
Proceeds from tower obligations	0
Repayments of short-term debt for purchases of inventory, property and equipment, net	0	0	0
Intercompany dividend paid	175	100
Proceeds from issuance of preferred stock		0
Dividends on preferred stock	0
Proceeds from exercise of stock options	0	0	0
Proceeds from issuance of common stock			0
Taxes paid related to net share settlement of stock awards	0	0
Other, net	0	0	0
Net cash provided by (used in) financing activities	(1,730)	(1,600)	0
Change in cash and cash equivalents	0	0	0
Beginning of year	0	0	0
End of year	0	0	0
Parent [Member]
Operating activities
Net cash provided by (used in) operating activities	(1)	9	299
Investing activities
Purchases of property and equipment	0	0	0
Purchases of spectrum licenses and other intangible assets, including deposits	0	0	0
Purchases of short-term investments	0
Short term affiliate loan receivable, net			0
Cash and cash equivalents acquired in MetroPCS business combination			737
Investment in subsidiaries	(1,905)	(1,700)
Other, net	0	0	0
Net cash provided by (used in) investing activities	(1,905)	(1,700)	737
Financing activities
Proceeds from capital contribution	0	0
Proceeds from issuance of long-term debt	0	0	0
Repayments of long-term debt and capital lease obligations	0	0	0
Proceeds from tower obligations	0
Repayments of short-term debt for purchases of inventory, property and equipment, net	0	0	0
Intercompany dividend paid	0	0
Proceeds from issuance of preferred stock		982
Dividends on preferred stock	(41)
Proceeds from exercise of stock options	47	27	137
Proceeds from issuance of common stock			1,787
Taxes paid related to net share settlement of stock awards	0	0
Other, net	0	0	0
Net cash provided by (used in) financing activities	6	1,009	1,924
Change in cash and cash equivalents	(1,900)	(682)	2,960
Beginning of year	2,278	2,960	0
End of year	378	2,278	2,960
Issuer [Member]
Operating activities
Net cash provided by (used in) operating activities	(4,504)	(5,145)	(1,203)
Investing activities
Purchases of property and equipment	0	0	0
Purchases of spectrum licenses and other intangible assets, including deposits	0	0	0
Purchases of short-term investments	(1,999)
Short term affiliate loan receivable, net			0
Cash and cash equivalents acquired in MetroPCS business combination			1,407
Investment in subsidiaries	0	0
Other, net	0	0	0
Net cash provided by (used in) investing activities	(1,999)	0	1,407
Financing activities
Proceeds from capital contribution	1,905	1,700
Proceeds from issuance of long-term debt	3,979	2,993	2,494
Repayments of long-term debt and capital lease obligations	0	0	0
Proceeds from tower obligations	140
Repayments of short-term debt for purchases of inventory, property and equipment, net	0	0	0
Intercompany dividend paid	0	0
Proceeds from issuance of preferred stock		0
Dividends on preferred stock	0
Proceeds from exercise of stock options	0	0	0
Proceeds from issuance of common stock			0
Taxes paid related to net share settlement of stock awards	0	0
Other, net	0	0	0
Net cash provided by (used in) financing activities	6,024	4,693	2,494
Change in cash and cash equivalents	(479)	(452)	2,698
Beginning of year	2,246	2,698	0
End of year	1,767	2,246	2,698
Guarantor Subsidiaries [Member]
Operating activities
Net cash provided by (used in) operating activities	9,940	9,364	4,380
Investing activities
Purchases of property and equipment	(4,724)	(4,317)	(4,025)
Purchases of spectrum licenses and other intangible assets, including deposits	(1,935)	(2,900)	(381)
Purchases of short-term investments	(998)
Short term affiliate loan receivable, net			300
Cash and cash equivalents acquired in MetroPCS business combination			0
Investment in subsidiaries	0	0
Other, net	96	(29)	(130)
Net cash provided by (used in) investing activities	(7,561)	(7,246)	(4,236)
Financing activities
Proceeds from capital contribution	0	0
Proceeds from issuance of long-term debt	0	0	0
Repayments of long-term debt and capital lease obligations	(57)	(1,019)	(9)
Proceeds from tower obligations	0
Repayments of short-term debt for purchases of inventory, property and equipment, net	(564)	(418)	(244)
Intercompany dividend paid	0	0
Proceeds from issuance of preferred stock		0
Dividends on preferred stock	(14)
Proceeds from exercise of stock options	0	0	0
Proceeds from issuance of common stock			0
Taxes paid related to net share settlement of stock awards	(156)	(73)
Other, net	79	32	(121)
Net cash provided by (used in) financing activities	(712)	(1,478)	(374)
Change in cash and cash equivalents	1,667	640	(230)
Beginning of year	697	57	287
End of year	2,364	697	57
Non-Guarantor Subsidiaries [Member]
Operating activities
Net cash provided by (used in) operating activities	154	18	69
Investing activities
Purchases of property and equipment	0	0	0
Purchases of spectrum licenses and other intangible assets, including deposits	0	0	0
Purchases of short-term investments	0
Short term affiliate loan receivable, net			0
Cash and cash equivalents acquired in MetroPCS business combination			0
Investment in subsidiaries	0	0
Other, net	0	0	0
Net cash provided by (used in) investing activities	0	0	0
Financing activities
Proceeds from capital contribution	0	0
Proceeds from issuance of long-term debt	0	0	0
Repayments of long-term debt and capital lease obligations	0	0	0
Proceeds from tower obligations	0
Repayments of short-term debt for purchases of inventory, property and equipment, net	0	0	0
Intercompany dividend paid	(175)	(100)
Proceeds from issuance of preferred stock		0
Dividends on preferred stock	0
Proceeds from exercise of stock options	0	0	0
Proceeds from issuance of common stock			0
Taxes paid related to net share settlement of stock awards	0	0
Other, net	0	0	0
Net cash provided by (used in) financing activities	(175)	(100)	0
Change in cash and cash equivalents	(21)	(82)	69
Beginning of year	94	176	107
End of year	$ 73	$ 94	$ 176