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Acquisitions, Divestitures and Exchanges (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2016	Jun. 30, 2016	Jun. 30, 2015	Feb. 29, 2016
Acquisitions
Cash paid for acquisitions and licenses			$ 46	$ 280
Federal Communications Commission deposit			143
Exchanges
Assets held for sale	$ 23	$ 23	23
Cash received from divestitures and exchanges			17	282
Gain on license sales and exchanges		9	9	$ 123
Aggregate license exchanges
Exchanges
Assets held for sale	15	15	15
Net cash to be received	1	1	1
License exchange 1
Exchanges
Assets held for sale	8	8	8
Net cash to be received					$ 28
License exchange 1, first closing
Exchanges
Cash received from divestitures and exchanges	13
Gain on license sales and exchanges	9
License Acquisitions \| Aggregate license acquisitions
Acquisitions
License acquisition agreement amount	$ 56	56	$ 56
Cash paid for acquisitions and licenses		$ 46