Annual report pursuant to Section 13 and 15(d)

Employee Retirement Benefits (Narrative) (Details)

v2.4.1.9
Employee Retirement Benefits (Narrative) (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]      
Maximum matching percentage by employer 6.00%us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent    
Contributions to the plan $ 528us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount $ 457us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount $ 471us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Expected contributions in 2015 76us-gaap_DefinedBenefitPlansEstimatedFutureEmployerContributionsInNextFiscalYear    
Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Investments used to fund the plan $ 3,756us-gaap_DefinedBenefitPlanAmountOfEmployerAndRelatedPartySecuritiesIncludedInPlanAssets
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
$ 3,645us-gaap_DefinedBenefitPlanAmountOfEmployerAndRelatedPartySecuritiesIncludedInPlanAssets
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member