Summary of Significant Accounting Policies - Fair Value of Financial Instruments (Details) (Fair Value, Inputs, Level 2 [Member])	Dec. 31, 2014 Rate	Dec. 31, 2013 Rate
term loan A facility [Member]
Debt Instrument [Line Items]
Long-term Debt, Fair Value, % of par value	99.50%	99.90%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Debt, Fair Value, % of par value	99.20%	99.60%