CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME [Parenthetical] (USD $) In Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Tax on Earnings (loss) of other equity accounted investments	$ 0	$ 0	$ 0	$ 0

Name:

crbn_TaxOnIncomeLossFromEquityMethodInvestmentsExcludingAssetLiquidationInvestments

Namespace Prefix:

crbn

Data Type:

xbrli:monetaryItemType

Balance Type:

debit

Period Type:

duration