Current report of foreign issuer pursuant to Rules 13a-16 and 15d-16 Amendments

Fair Value Measurements (Schedule of Reconciliation of Fair Value Measurements of Assets and Liabilities Utilizing Level 3 Inputs) (Details))

v2.4.1.9
Fair Value Measurements (Schedule of Reconciliation of Fair Value Measurements of Assets and Liabilities Utilizing Level 3 Inputs) (Details)) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 12 Months Ended
Mar. 31, 2015
Dec. 31, 2014
Reconciliation of Fair Value Measurements of Assets and Liabilities Utilizing Level 3 Inputs [Roll Forward]    
Fair value at the beginning of the period $ 35,656us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue $ 29,025us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue
Cash settlements    (10,795)us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements
Additions    43,576us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases
Change in fair value recognized in earnings (13,256)us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1 (26,150)us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1
Fair value at the end of the period $ 22,400us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue $ 35,656us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue