Basis of Presentation (Assets and Liabilities Measured at Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Assets, Fair Value
Indemnification - Sale of SSL	$ 2,410	$ 2,410
Money Market Funds [Member] | Level 1 [Member]
Assets, Fair Value
Cash equivalents	254,623	254,552
Money Market Funds [Member] | Level 2 [Member]
Assets, Fair Value
Cash equivalents
Sale of SSL, Nov. 02, 2012 [Member] | Level 2 [Member]
Assets, Fair Value
Indemnification - Sale of SSL
Sale of SSL, Nov. 02, 2012 [Member] | Level 3 [Member]
Assets, Fair Value
Indemnification - Sale of SSL	2,410	2,410
Globalstar do Brasil S.A. [Member] | Level 3 [Member]
Liabilities, Fair Value
Indemnification - Globalstar do Brasil S.A.	$ 171	$ 184