Summary of Significant Accounting Policies - Schedule Of Cumulative Effects Change (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Jan. 01, 2017	Dec. 31, 2016
Assets:
Trade accounts receivable and contract assets, net	$ 217,524		$ 189,737	$ 196,840
Other current assets	17,222		92,204	91,671
Investments in unconsolidated entities	160,669		168,344	161,427
Other noncurrent assets, net	262,866		237,359	214,814
Total assets	8,850,446		8,772,906	8,750,014
Liabilities:
Contract liabilities	74,135		64,417	65,959
Accrued expenses and other	72,464		82,902	82,647
Deferred tax liabilities, net	471,259		439,145	436,023
Other noncurrent liabilities	124,694		124,435	128,503
Total liabilities	4,591,716		4,570,396	4,572,629
Stockholders’ Equity:
Accumulated other comprehensive loss	(160,947)		(119,687)	(130,154)
Accumulated earnings	808,330		735,974	721,316
Total EchoStar Corporation stockholders’ equity	4,258,730	$ 4,244,252	4,202,510	4,177,385	$ 3,895,819	$ 3,856,724	$ 4,021,313	$ 4,006,805
Total liabilities and stockholders’ equity	8,850,446		8,772,906	8,750,014
Accounting Standards Update 2016-01
Stockholders’ Equity:
Accumulated other comprehensive loss	40,407		10,467
Accumulated earnings	(40,407)		(10,467)
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Assets:
Trade accounts receivable and contract assets, net	8,511		(7,103)
Other current assets	(533)		533
Investments in unconsolidated entities	(6,071)		6,917
Other noncurrent assets, net	(33,310)		22,545
Total assets	(31,403)		22,892
Liabilities:
Contract liabilities	971		(1,542)
Accrued expenses and other	(255)		255
Deferred tax liabilities, net			3,122
Other noncurrent liabilities	2,234		(4,068)
Total liabilities	(1,763)		(2,233)
Stockholders’ Equity:
Accumulated other comprehensive loss	0		0
Accumulated earnings	(29,640)		25,125
Total EchoStar Corporation stockholders’ equity	(29,640)		25,125
Total liabilities and stockholders’ equity	(31,403)		22,892
Calculated under Revenue Guidance in Effect before Topic 606
Assets:
Trade accounts receivable and contract assets, net				196,840
Other current assets				91,671
Investments in unconsolidated entities				161,427
Other noncurrent assets, net				214,814
Total assets				8,750,014
Liabilities:
Contract liabilities				65,959
Accrued expenses and other				82,647
Deferred tax liabilities, net				436,023
Other noncurrent liabilities				128,503
Total liabilities				4,572,629
Stockholders’ Equity:
Total EchoStar Corporation stockholders’ equity				4,177,385
Total liabilities and stockholders’ equity				8,750,014
Calculated under Revenue Guidance in Effect before Topic 606 | Accounting Standards Update 2014-09
Assets:
Trade accounts receivable and contract assets, net	226,035
Other current assets	16,689
Investments in unconsolidated entities	154,598
Other noncurrent assets, net	229,556
Total assets	8,819,043
Liabilities:
Contract liabilities	75,106
Accrued expenses and other	72,209
Other noncurrent liabilities	126,928
Total liabilities	4,589,953
Stockholders’ Equity:
Total EchoStar Corporation stockholders’ equity	4,229,090
Total liabilities and stockholders’ equity	$ 8,819,043
Calculated Under Revenue Guidance In Effect Before Topic 606 And Accounting Standards Update 2016-01
Stockholders’ Equity:
Accumulated other comprehensive loss				(130,154)
Accumulated earnings				$ 721,316
Accumulated Earnings | Accounting Standards Update 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets			(10,500)
Accumulated Earnings | Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets			$ 25,100