Summary of Significant Accounting Policies - Fair Value of Financial Instruments (Details) (Fair Value, Inputs, Level 2 [Member])	Dec. 31, 2012	Dec. 31, 2011
Senior Secured Term Loan A [Member]
Debt Instrument [Line Items]
Long-term Debt, Fair Value, % of par value	99.30%
Senior Secured Term Loan B [Member]
Debt Instrument [Line Items]
Long-term Debt, Fair Value, % of par value	99.90%	99.00%
Senior secured notes [Member]
Debt Instrument [Line Items]
Long-term Debt, Fair Value, % of par value		108.50%