SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 30, 2019	Jul. 31, 2019	Jan. 01, 2019	Dec. 31, 2013	May 31, 2013
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 3,382,000	$ 3,610,000	$ 3,966,000
Provision, net of recoveries	1,747,000	1,398,000	1,256,000
Write-offs and other adjustments	(2,177,000)	(1,626,000)	(1,612,000)
Balance at end of period	2,952,000	3,382,000	3,610,000
Inventory
Inventory	16,341,000	14,274,000
Write-down of inventory	416,000	0	843,000
Deferred Financing Costs
Deferred financing costs	43,600,000	24,400,000
Debt instrument, interest rate (percentage)				13.50%	15.00%
Foreign Currency
Foreign currency translation adjustments	(707,000)	3,164,000	(1,945,000)
Foreign currency transaction gain (loss)	100,000	(3,100,000)	(2,200,000)
Asset Retirement Obligation
Asset retirement obligation	1,467,000	1,459,000
Research and Development Expenses
Research and development expense	3,200,000	2,700,000	3,800,000
Advertising Expenses
Advertising expense	$ 3,400,000	3,600,000	$ 2,500,000
8.00% Convertible Senior Notes Issued in 2013
Deferred Financing Costs
Debt instrument, interest rate (percentage)	8.00%		8.00%				8.00%	8.00%
Minimum
Leases [Abstract]
Remaining lease term	1 year
Warranty Expense
Warranty term	90 days
Maximum
Leases [Abstract]
Remaining lease term	12 years
Warranty Expense
Warranty term	1 year
Space component
Property and Equipment
Estimated useful life (in years)	15 years
Ground component
Property and Equipment
Estimated useful life (in years)	15 years
Software, Facilities and Equipment | Minimum
Property and Equipment
Estimated useful life (in years)	3 years
Software, Facilities and Equipment | Maximum
Property and Equipment
Estimated useful life (in years)	10 years
Building
Property and Equipment
Estimated useful life (in years)	18 years
Purchased products, including subscriber equipment devices
Inventory
Inventory	$ 12,000,000	8,600,000
Ground infrastructure assets
Inventory
Inventory	4,300,000	$ 5,700,000.0
Mothballed Gateway Location | Disposal Group, Held-for-sale, Not Discontinued Operations
Property and Equipment
Assets held for sale	500,000					$ 1,600,000
Asset impairment	$ 1,100,000