Annual report pursuant to Section 13 and 15(d)

Fair Value Measurement - Fair Value of Liabilities Measured on a Recurring Basis (Details)

v2.4.1.9
Fair Value Measurement - Fair Value of Liabilities Measured on a Recurring Basis (Details) (Recurring, Fair Value, Inputs, Level 2, Interest Rate Swap, USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Recurring | Fair Value, Inputs, Level 2 | Interest Rate Swap
   
Liabilities, Fair Value Disclosure [Abstract]    
Interest rate swap instruments $ 4,430us-gaap_DerivativeLiabilities
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateSwapMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
$ 4,268us-gaap_DerivativeLiabilities
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateSwapMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember