Employer Sponsored Retirement Savings Plan (Details) (USD $) In Millions, unless otherwise specified	10 Months Ended	12 Months Ended
	Oct. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Employer Sponsored Retirement Savings Plan
Compensation related expenses		0
Predecessor
Employer Sponsored Retirement Savings Plan
Employer matching contribution as percentage of first 3% of employee contributions		100.00%
Percentage of first eligible employee contribution matched 100%		3.00%
Employer matching contribution as percentage of the next 2% of employee contributions		50.00%
Percentage of next eligible compensation matched 50%		2.00%
Eligible employee compensation matched by the employer (as a percent)		4.00%
Participants vested in employer matching contributions (as a percent)		100.00%
Participants vested in employer's discretionary profit sharing contributions (as a percent)		100.00%
Period of completed years of service for participant's vesting in employer's discretionary profit sharing contributions		6 years
Participants vested in employer's discretionary profit sharing contributions after one year of service (as a percent)		0.00%
Period of completed years of service for participant's 0% vesting in employer's discretionary profit sharing contributions		1 year
Participants vested in employer's discretionary profit sharing contributions after two years of service (as a percent)		20.00%
Period of completed years of service for participant's 20% vesting in employer's discretionary profit sharing contributions		2 years
Employer matching contributions	0.2		0.2	0.2
Employer's discretionary profit sharing contributions	$ 0		$ 0	$ 0