Commitments and Contingencies - Narrative Part 2 (Details)						3 Months Ended			6 Months Ended		12 Months Ended	126 Months Ended
	Apr. 05, 2018 USD ($)	May 22, 2017 USD ($)	Oct. 03, 2016	Sep. 23, 2016 USD ($)	Feb. 12, 2015 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jun. 30, 2018 USD ($) item	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 05, 2017 USD ($)
Loss contingencies
Payment to acquire interest in non-controlling investments in certain entities												$ 11,000,000,000
Total investment										$ 90,381,000		21,000,000,000
Dividend paid to DOC					$ 8,250,000,000
General and administrative expenses						$ 183,594,000	$ 179,298,000		$ 345,278,000	$ 304,608,000
Other accrued expenses
Loss contingencies
Litigation expense											$ 41,000,000
Satellite transponder guarantees
Loss contingencies
Guarantees for payments						84,000,000			84,000,000			84,000,000
Telemarketing Litigation [Member]
Loss contingencies
Period of injunctive relief sought from placing any outbound telemarketing calls to market or promote its goods or services			5 years
Litigation expense							$ 255,000,000		$ 25,000,000
Litigation accrual													$ 280,000,000
Number of telemarketing calls | item									51,119
Litigation per call damages									$ 400
Judgment in favor of the court	$ 61,000,000
Telemarketing Litigation [Member] | Other accrued expenses
Loss contingencies
Litigation accrual						280,000,000			280,000,000			280,000,000
Litigation per call damages		$ 1,200
Krakauer Action
Loss contingencies
Litigation expense								$ 20,000,000
Krakauer Action | Other accrued expenses
Loss contingencies
Litigation accrual						$ 61,000,000			$ 61,000,000			$ 61,000,000
AWS 3 Auction | Northstar Wireless or Northstar Spectrum | Vermont National Telephone Company
Loss contingencies
Bidding Credit				$ 3,300,000,000
Loss Contingency Recovery Amount				10,000,000,000
Bidding credit value				3,300,000,000
AWS 3 Auction | Maximum | Northstar Wireless or Northstar Spectrum | Vermont National Telephone Company
Loss contingencies
Claim amount				11,000
AWS 3 Auction | Minimum | Northstar Wireless or Northstar Spectrum | Vermont National Telephone Company
Loss contingencies
Claim amount				$ 5,500