Annual report pursuant to Section 13 and 15(d)

Derivative Financial Instruments (Narrative) (Details)

v2.4.1.9
Derivative Financial Instruments (Narrative) (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Derivative Financial Instruments [Abstract]      
Maximum net exposure to counterparty $ 3,422bde_MaximumNetExposureToCounterparty    
Cash flow hedge gain (loss) reclassified to revenue 228us-gaap_Revenues 804us-gaap_Revenues  
Accumulated derivative instrument gain (loss) (1,891)us-gaap_AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax (611)us-gaap_AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax  
Adjustment to accumulated other comprehensive income $ 2,502us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax $ (442)us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax $ (675)us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax