Annual report pursuant to Section 13 and 15(d)

Accumulated Other Comprehensive Income (Loss) - Summary of Changes in Accumulated Other Comprehensive Income (Loss) (Detail)

v2.4.1.9
Accumulated Other Comprehensive Income (Loss) - Summary of Changes in Accumulated Other Comprehensive Income (Loss) (Detail) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Balance at December 31, 2013 $ (8,582)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax    
Other comprehensive income (loss) before reclassifications (4,569)us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax    
Amounts reclassified out of accumulated other comprehensive income (loss) 6,727us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax    
Other comprehensive income (loss) 2,158us-gaap_OtherComprehensiveIncomeLossNetOfTax 11,381us-gaap_OtherComprehensiveIncomeLossNetOfTax 1,527us-gaap_OtherComprehensiveIncomeLossNetOfTax
Balance at December 31, 2014 (6,424)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax (8,582)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax  
Gains and Losses on Cash Flow Hedges [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Balance at December 31, 2013 (8,859)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember
   
Other comprehensive income (loss) before reclassifications (3,841)us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember
   
Amounts reclassified out of accumulated other comprehensive income (loss) 6,727us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember
   
Other comprehensive income (loss) 2,886us-gaap_OtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember
   
Balance at December 31, 2014 (5,973)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember
   
Defined Benefit Pension Plan [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Balance at December 31, 2013 277us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember
   
Other comprehensive income (loss) before reclassifications (728)us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember
   
Other comprehensive income (loss) (728)us-gaap_OtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember
   
Balance at December 31, 2014 $ (451)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember