Annual report pursuant to Section 13 and 15(d)

Stock-based and Long-Term Compensation - Schedule of Valuation Assumptions (Details)

v2.4.1.9
Stock-based and Long-Term Compensation - Schedule of Valuation Assumptions (Details) (Employee Stock Option, Common Class A)
12 Months Ended
Dec. 31, 2012
Employee Stock Option | Common Class A
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Risk-free interest rate 0.89%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Estimated life in years 4 years 9 months 4 days
Dividend yield 0.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Volatility 43.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember