Derivative Financial Instruments (Details) (USD $)		4 Months Ended	1 Months Ended			12 Months Ended
	Dec. 31, 2012	Apr. 30, 2010 Predecessor	Mar. 31, 2012 Interest rate contract	Jun. 30, 2009 Interest rate contract quotation	Feb. 29, 2008 Interest rate contract agreement	Dec. 31, 2009 Interest rate contract	Dec. 31, 2012 Interest rate contract
Derivatives
Component of agreement for Term loan B			$ 470,000,000		$ 600,000,000
Interest rate basis for term loan borrowings			LIBOR		LIBOR
Derivative Cap (as a percent)			1.00%
Derivative Designated as Cash Flow Hedges
Derivative Assets, current							2,000
Derivative Assets, non-current							30,000
Derivative Assets							32,000
Net deferred losses on derivative instruments expected to be reclassified to operations during the next twelve months	(600,000)
Loss as a result of termination of interest rate swap recorded in other expense						16,400,000
Number of interest rate swap agreements entered into by the entity					2
Notional amount of each interest rate swap agreement			470,000,000		300,000,000
Interest rates for interest rate swap, low end of range (as a percent)				5.325%
Interest rates for interest rate swap, high end of range (as a percent)				5.358%
Average range of interest rates for interest rate swap (as a percent)				5.342%
Number of independent quotations provided for replacement transactions				4
Summary of the changes recorded in accumulated other comprehensive Income (Loss)
Balance at the beginning of the period	(501,000)	1,270,000
Reclassification to other (income) expense , net		(559,000)
Balance at the end of the period	$ (501,000)	$ 711,000