Annual report pursuant to Section 13 and 15(d)

Derivative Instruments - Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) (Details)

v2.4.1.9
Derivative Instruments - Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) (Details) (Interest Rate Contract [Member], USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative Instruments, Gain (Loss) in Other Comprehensive Income $ 0us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet $ (30)us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet $ (136)us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet
Derivative Instruments, Gain (Loss) Reclassified from AOCI into Interest Expenese (Effective Portion) 0us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet 0us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet 0us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
Derivative Instruments, Losses Reclassified into Earnings as a Result of Discontinuance of Cash Flow Hedge Accounting 0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet 166us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet 0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
Designated as Hedging Instrument [Member]
     
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative Instruments, Gain (Loss) in Other Comprehensive Income 0us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
21,297us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
(21,290)us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
Derivative Instruments, Gain (Loss) Reclassified from AOCI into Interest Expenese (Effective Portion) 0us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
0us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
0us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
Derivative Instruments, Losses Reclassified into Earnings as a Result of Discontinuance of Cash Flow Hedge Accounting 0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
5,807us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
Not Designated as Hedging Instrument [Member]
     
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative Instruments, Gain (Loss) in Other Comprehensive Income 0us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
0us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
(5,814)us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Derivative Instruments, Gain (Loss) Reclassified from AOCI into Interest Expenese (Effective Portion) 0us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
0us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
0us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Derivative Instruments, Losses Reclassified into Earnings as a Result of Discontinuance of Cash Flow Hedge Accounting $ 0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
$ 0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
$ 0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember