Financial Instruments, Derivative Instruments And Hedging (Schedule of Unhedged Foreign Currency Transactions) (Detail) In Thousands, unless otherwise specified	Sep. 30, 2012 USD ($)	Sep. 30, 2012 JPY (¥)	Sep. 30, 2012 Euros [Member] USD ($)	Sep. 30, 2012 Euros [Member] EUR (€)
Trading Activity, Gains and Losses, Net [Line Items]
Future revenues denominated in foreign currencies not hedged	$ 860	¥ 67,023	$ 22,007	€ 17,113
Future expenditure denominated in foreign currency not hedged	$ 37,040	¥ 2,887,087	$ 2,208	€ 1,717

Future expenditures denominated in foreign currency contracts that were unhedged as of the balance sheet date.

No definition available.

Name:	lorl_FutureExpenditureUnhedgedForeignCurrencyContracts
Namespace Prefix:	lorl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant