• Filing Date: 2015-03-10
  • Form Type: 10-K
  • Description: Annual report
v2.4.1.9
Fair Value Measurements - Schedule of Fair Value Information for Financial Assets and Liabilities Carried on Balance Sheet (Parenthetical) (Detail)
Dec. 31, 2014
Dec. 31, 2013
Dec. 11, 2013
Assets And Liabilities Carrying Value And Fair Value [Line Items]      
Debt instrument stated interest rate   3.875%us-gaap_DebtInstrumentInterestRateStatedPercentage  
Senior Notes [Member]      
Assets And Liabilities Carrying Value And Fair Value [Line Items]      
Fixed annual rate of interest 8.00%us-gaap_LongTermDebtPercentageBearingFixedInterestRate
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
   
Convertible Senior Notes [Member]      
Assets And Liabilities Carrying Value And Fair Value [Line Items]      
Debt instrument stated interest rate 3.875%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_ConvertibleDebtMember
3.875%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_ConvertibleDebtMember
3.875%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_ConvertibleDebtMember
Fair Value, Measurements, Recurring [Member] | Senior Notes [Member]      
Assets And Liabilities Carrying Value And Fair Value [Line Items]      
Fixed annual rate of interest 8.00%us-gaap_LongTermDebtPercentageBearingFixedInterestRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
8.00%us-gaap_LongTermDebtPercentageBearingFixedInterestRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
 
Fair Value, Measurements, Recurring [Member] | Convertible Senior Notes [Member]      
Assets And Liabilities Carrying Value And Fair Value [Line Items]      
Debt instrument stated interest rate 3.875%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_ConvertibleDebtMember
3.875%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_ConvertibleDebtMember