Marketable Securities - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Investments Debt And Equity Securities [Abstract]
Gross Unrealized Losses	$ 8

This item represents the excess of amortized cost basis over fair value of securities in a loss position and which are categorized as held-to-maturity.

No definition available.

Name:	orbc_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
Namespace Prefix:	orbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant