Basis of Presentation (Assets and Liabilities Measured at Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets and Liabilities
Indemnification receivable from SS/L for pre-closing taxes	$ 2,410	$ 2,410
Money Market Funds [Member] | Level 1 [Member]
Assets and Liabilities
Cash equivalents	249,066	251,742
Money Market Funds [Member] | Level 2 [Member]
Assets and Liabilities
Cash equivalents
Sale of SS/L, Nov. 02, 2012 [Member] | Level 2 [Member]
Assets and Liabilities
Indemnification receivable from SS/L for pre-closing taxes
Sale of SS/L, Nov. 02, 2012 [Member] | Level 3 [Member]
Assets and Liabilities
Indemnification receivable from SS/L for pre-closing taxes	2,410	2,410
Globalstar do Brasil S.A. [Member] | Level 2 [Member]
Assets and Liabilities
Indemnification liabilities
Globalstar do Brasil S.A. [Member] | Level 3 [Member]
Assets and Liabilities
Indemnification liabilities	$ 285	$ 293