Income Taxes (Summary of Changes to Company's Liabilities For UTPs) (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017
Income Taxes [Abstract]
Opening balance - January 1	$ 61,182	$ 68,658
Current provision for potential additional interest	2,018	2,069
Ending balance	$ 63,200	$ 70,727

This element represents the amount of interest expense accrued during the period for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity.

No definition available.

Name:	lorl_Unrecognizedtaxbenefitsinterestonincometaxesaccruedduringperiod
Namespace Prefix:	lorl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration