Commitments and Contingencies (Details) $ in Millions											1 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended	84 Months Ended	141 Months Ended
	Jul. 26, 2019 USD ($) item	Jun. 07, 2018 USD ($)	Jun. 06, 2018	May 11, 2017 USD ($)	Jul. 01, 2016 USD ($)	Aug. 18, 2015 USD ($)	Apr. 29, 2014 USD ($) segment	Oct. 29, 2013	Mar. 09, 2012	Mar. 09, 2012 USD ($)	Jan. 31, 2017	Mar. 31, 2018 USD ($) item	Sep. 30, 2019 USD ($) store item	Dec. 31, 2008 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2019 USD ($) item	Dec. 31, 2018 USD ($)	Apr. 13, 2017 USD ($) item
Spectrum Investments
Payment to acquire certain wireless licenses and related assets															$ 11,000.0	$ 21,000.0
Period in which at least 20% of population served to avoid payment of damages	3 years
Number of spectrum bands | item	4
Commitments relating to AWS-3 Auction
Noncontrolling Interest in Variable Interest Entity													$ 10,000.0			10,000.0
MVDDS Licenses
Spectrum Investments
Number of geographical license areas | item													82
MVDDS Licenses | Maximum
Spectrum Investments
Number of geographical license areas | item													214
LMDS Licenses
Spectrum Investments
Number Of Markets | item													4
Wireless
Spectrum Investments
Payment to acquire certain wireless licenses and related assets																11,000.0
H Block Licenses
Spectrum Investments
Payment to acquire certain wireless licenses and related assets							$ 1,672.0
Number of wireless spectrum licenses | segment							176
H Block Licenses | Minimum
Spectrum Investments
Final Build-out Requirement (as a percent)													75.00%
AWS-4 Satellites | Maximum
Spectrum Investments
Percent of coverage on available licensed geographic areas	70.00%
AWS-4 Satellites | Minimum
Spectrum Investments
Percent of coverage on available licensed geographic areas	20.00%
700 MHz Licenses
Spectrum Investments
Payment to acquire certain wireless licenses and related assets														$ 712.0
Modified 700 MHz Final Build-out Requirement (as a percent)								70.00%
700 MHz Licenses | Maximum
Spectrum Investments
Percent of coverage on available licensed geographic areas	70.00%
700 MHz Licenses | Minimum
Spectrum Investments
Percent of coverage on available licensed geographic areas	20.00%
600 MHz Licenses
Spectrum Investments
Number of wireless spectrum licenses | item																		486
Build-out requirement accelerated period											2 years
Aggregate Bid Price																		$ 6,211.0
Licenses Renewal Period													39 months
600 MHz Licenses | Maximum
Spectrum Investments
Percent of coverage on available licensed geographic areas	75.00%												75.00%
600 MHz Licenses | Minimum
Spectrum Investments
Percent of coverage on available licensed geographic areas	70.00%												40.00%
28 GHz and 24 GHz Licenses
Spectrum Investments
Aggregate Bid Price													$ 15.0			15.0
AWS H Block licenses | Maximum
Spectrum Investments
Percent of coverage on available licensed geographic areas	70.00%
AWS H Block licenses | Minimum
Spectrum Investments
Percent of coverage on available licensed geographic areas	20.00%
DBSD North America and TerreStar Transactions | Wireless
Spectrum Investments
Purchase price										$ 2,860.0
AWS-4 Final Build-out Requirement (as a percent)													70.00%
DBSD North America and TerreStar Transactions | AWS-4 Satellites
Spectrum Investments
Ownership percentage									100.00%
Prior Arrangement | Northstar Licenses
Spectrum Investments
Non-payment gross winning bids													$ 2,226.0			2,226.0
Spectrum Purchase Agreement
Spectrum Investments
Period within which divesture to be completed after receipt of FCC approval													3 years
Threshold divesture deadline extension period													5 days
Spectrum lease back period													3 years
per-Pop rate													$ 68.0
Decrease in purchase price due to failure to complete rebanding activities													72.0
Damages sought value in case of breach of agreement													$ 72.0
Master Network Service Agreement [Member]
Spectrum Investments
Service receipt period													2 years
Maximum Permitted Ownership Percent													50.00%
service pass through costs and out of pocket expenses charging period													36 months
Threshold Ownership Percentage Of Not Permitted Owners													50.00%
Percentage Of Wireless Communication Business Assets Are Sold													50.00%
Percentage Of Voting Power Or Economic Value Held By Restricted Persons													50.00%
Provision For New User After Change Of Control													6 months
Option Agreement
Spectrum Investments
Number of cell sites | item													20,000
Number of retail stores | store													400
Period in which cell sites are scheduled to be decommissioned													5 years
Option agreement term													5 years
Period after closing of prepaid business sale, transfer asset request is admissible	1 year
Period within closing of prepaid business sale, required to offer nationwide postpaid retail mobile wireless service	1 year
Damages To Be Paid In Case Of Breach Of Agreement	$ 360.0
Percentage of purchase price	10.00%
Percentage of population served	20.00%
Status of negotiation period	90 days
Threshold period for involvement of DOJ	180 days
Period obliged to provide DOJ with description of deployment efforts	180 days
Public Commitment Period	60 days
Term of final judgement from the date of its entry with the District Court.	7 years
Term of final judgement if DOJ gives notice	5 years
Spectrum Lease Period	6 years
Option Agreement | AWS-4 Satellites
Spectrum Investments
Damages To Be Paid In Case Of Breach Of Agreement	$ 2,200.0
Northstar Spectrum And SNR Holdco
Commitments relating to AWS-3 Auction
Noncontrolling Interest in Variable Interest Entity													$ 10,000.0			$ 10,000.0	$ 10,000.0
Northstar Spectrum And SNR Holdco | American III
Spectrum Investments
Number of wireless spectrum licenses | item													244			244
Northstar Spectrum And SNR Holdco | AWS-3 Licenses
Spectrum Investments
Interim Build-out Requirement (as a percent)													40.00%
Final Build-out Requirement (as a percent)													75.00%
Accelerated period to meet Final Build-Out Requirement on failure to meet Interim Build-Out Requirement													2 years
Northstar Spectrum And SNR Holdco | SNR Licenses
Commitments relating to AWS-3 Auction
Percentage of bidding credit						25.00%
Northstar Spectrum And SNR Holdco | Prior Arrangement | SNR Licenses
Commitments relating to AWS-3 Auction
Number of licenses returned | item													113
Northstar Spectrum And SNR Holdco | Northstar Operative Agreement | American II
Spectrum Investments
Debt outstanding amount												$ 6,870.0
Northstar Wireless or Northstar Spectrum
Spectrum Investments
Interim payment percentage													15.00%
Re-Auction payment													$ 1,892.0
Overpayment Of Interim Payment													$ 334.0
Northstar Wireless or Northstar Spectrum | Preferred Class A
Spectrum Investments
Ownership percentage													100.00%
Northstar Wireless or Northstar Spectrum | Class B common stock
Spectrum Investments
Ownership percentage													85.00%
Commitments relating to AWS-3 Auction
Controlling interest owned by other companies													15.00%
Northstar Wireless or Northstar Spectrum | Northstar Manager LLC
Commitments relating to AWS-3 Auction
Equity contribution												133.0
Northstar Wireless or Northstar Spectrum | American II
Spectrum Investments
Loan made													$ 69.0
Window of days for management to put its interest		90 days	30 days
Additional days allowed for management to put its interest		90 days
Commitments relating to AWS-3 Auction
Equity contribution												7,621.0
Northstar Wireless or Northstar Spectrum | American II | Maximum
Spectrum Investments
Preferred stock quarterly distribution (as a percent)		12.00%
Northstar Wireless or Northstar Spectrum | American II | Minimum
Spectrum Investments
Preferred stock quarterly distribution (as a percent)		8.00%
Northstar Wireless or Northstar Spectrum | AWS 3 Auction
Spectrum Investments
Interim Payment													$ 334.0
Interim payment percentage													15.00%
Northstar Wireless or Northstar Spectrum | Northstar Licenses
Spectrum Investments
Number of wireless spectrum licenses | item													261			261
Commitments relating to AWS-3 Auction
Gross winning bids													$ 5,619.0
Bidding credit value						$ 1,961.0
Northstar Wireless or Northstar Spectrum | AWS-3 Licenses
Spectrum Investments
Non-payment gross winning bids													2,226.0			$ 2,226.0
Commitments relating to AWS-3 Auction
Gross winning bids													$ 7,845.0
Percentage of bidding credit													25.00%
Net winning bid													$ 5,884.0
Number of licenses returned | item													84
Northstar Wireless or Northstar Spectrum | Northstar Operative Agreement | American II
Spectrum Investments
Principal amount of debt												$ 500.0
Loan balance maturity period			7 years
Removal of consent for unsecured financing and equipment financing		$ 25.0
Northstar Wireless or Northstar Spectrum | Northstar Operative Agreement | American II | Preferred Class A
Spectrum Investments
Number shares issued in conversion | item												6,870,493
Preferred stock quarterly distribution (as a percent)												12.00%
Northstar Wireless or Northstar Spectrum | Northstar Operative Agreement | American II | Maximum
Spectrum Investments
Interest rate (as a percent)												12.00%
Northstar Wireless or Northstar Spectrum | Northstar Operative Agreement | American II | Minimum
Spectrum Investments
Interest rate (as a percent)												6.00%
SNR Wireless or SNR Wireless Holdco
Spectrum Investments
Re-Auction payment													$ 1,029.0
Overpayment Of Interim Payment													$ 182.0
SNR Wireless or SNR Wireless Holdco | Preferred Class A
Spectrum Investments
Ownership percentage													100.00%
SNR Wireless or SNR Wireless Holdco | Class B common stock
Spectrum Investments
Ownership percentage													85.00%
Commitments relating to AWS-3 Auction
Controlling interest owned by other companies													15.00%
SNR Wireless or SNR Wireless Holdco | Maximum
Spectrum Investments
Preferred stock quarterly distribution (as a percent)		12.00%
SNR Wireless or SNR Wireless Holdco | Minimum
Spectrum Investments
Preferred stock quarterly distribution (as a percent)		8.00%
SNR Wireless or SNR Wireless Holdco | SNR Wireless Management LLC
Commitments relating to AWS-3 Auction
Equity contribution												$ 93.0
SNR Wireless or SNR Wireless Holdco | American III
Spectrum Investments
Loan made													$ 344.0
Debt outstanding amount												5,065.0
Principal amount of debt												500.0
Window of days for management to put its interest		90 days	30 days
Additional days allowed for management to put its interest		90 days
Commitments relating to AWS-3 Auction
Equity contribution												$ 5,590.0
Gross winning bids													$ 4,271.0
SNR Wireless or SNR Wireless Holdco | American III | Preferred Class A
Spectrum Investments
Number shares issued in conversion | item												5,065,415
Preferred stock quarterly distribution (as a percent)												12.00%
SNR Wireless or SNR Wireless Holdco | American III | Maximum
Spectrum Investments
Interest rate (as a percent)												12.00%
SNR Wireless or SNR Wireless Holdco | American III | Minimum
Spectrum Investments
Interest rate (as a percent)													6.00%			6.00%
SNR Wireless or SNR Wireless Holdco | AWS 3 Auction
Spectrum Investments
Non-payment gross winning bids													$ 1,211.0			$ 1,211.0
Commitments relating to AWS-3 Auction
Gross winning bids													5,482.0
Net winning bid													4,112.0
Bid withdrawal payment													8.0
SNR Wireless or SNR Wireless Holdco | AWS-3 Licenses
Spectrum Investments
Non-payment gross winning bids													$ 1,211.0			1,211.0
SNR Wireless or SNR Wireless Holdco | AWS-3 Licenses | SNR Wireless Management LLC
Spectrum Investments
Interim payment percentage													15.00%
SNR Wireless or SNR Wireless Holdco | SNR Licenses
Spectrum Investments
Interim Payment													$ 182.0
Non-payment gross winning bids													1,211.0			$ 1,211.0
Additional Bid Withdrawal Payment													$ 3.0
Commitments relating to AWS-3 Auction
Bidding credit value						$ 1,370.0
SNR Wireless or SNR Wireless Holdco | SNR Operative Agreement | American III
Spectrum Investments
Loan balance maturity period		10 years	7 years
Removal of consent for unsecured financing and equipment financing		$ 25.0
FCC Wireless Bureau | Auction 1000
Spectrum Investments
Payment to acquire certain wireless licenses and related assets					$ 1,500.0
Payment of remaining balance of winning bid				$ 4,711.0
SNR Credit Agreement | SNR Wireless or SNR Wireless Holdco
Spectrum Investments
Loan made												$ 500.0
Northstar Credit Agreement | Northstar Wireless or Northstar Spectrum | American II
Spectrum Investments
Loan made												$ 500.0