Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2021	Dec. 31, 2020
Income Tax Contingency [Line Items]
Corona virus aid relief and economic security act, income tax expense (benefit)	$ (2,200)		$ (5,700)
Deferred tax assets		$ 29,280			$ 27,339
Accrued tax penalties		0
Unrecognized tax benefits, interest on income taxes accrued		4,100
Unrecognized tax benefits that would reduce the income tax provision		9,100
Unrecognized Tax Benefits		43,000
Forecast [Member]
Income Tax Contingency [Line Items]
Reduction to unrecognized tax benefits				$ 16,400
Telesat Canada [Member] | Federal [Member]
Income Tax Contingency [Line Items]
Fed Tax On GILTI		0			0
Deferred tax assets		$ 0			$ 0