Equity-Based Compensation (Details 3) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Employees
Weighted average assumptions utilized for purposes of valuing grants of options to employees and non-employee directors
Risk free interest rate (as a percent)	0.95%	0.66%	1.67%
Expected volatility (as a percent)	59.00%	57.00%	51.00%
Expected option term	5 years	4 years 7 months 28 days	5 years 6 months
Non-Employee Directors
Weighted average assumptions utilized for purposes of valuing grants of options to employees and non-employee directors
Risk free interest rate (as a percent)	0.85%	0.68%	1.36%
Expected volatility (as a percent)	46.00%	56.00%	51.00%
Expected option term	4 years	4 years	4 years
Stock options
Options
Outstanding at beginning of year (in shares)	2,190,073
Granted (in shares)	1,120,050
Exercised (in shares)	(123,658)
Expired and/or forfeited (in shares)	(366,789)
Outstanding at end of year (in shares)	2,819,676	2,190,073
Outstanding at end of year - vested and unvested expected to vest (in shares)	2,644,475
Exercisable at end of year (in shares)	1,003,804
Weighted Average Exercise Price
Outstanding at beginning of year (in dollars per share)	$ 23.07
Granted (in dollars per share)	$ 18.73
Exercised (in dollars per share)	$ 15.02
Expired and/or forfeited (in dollars per share)	$ 26.06
Outstanding at end of year (in dollars per share)	$ 21.31	$ 23.07
Outstanding at end of year - vested and unvested expected to vest (in dollars per share)	$ 21.51
Exercisable at end of year (in dollars per share)	$ 28.75
Outstanding at end of year	7 years 1 month 6 days
Outstanding at end of year - vested and unvested expected to vest	7 years 1 month 6 days
Exercisable at end of year	5 years 2 months 12 days
Aggregate Intrinsic Value
Outstanding at end of year	$ 17.5
Outstanding at end of year - vested and unvested expected to vest	16.4
Exercisable at end of year	4.0
Additional Disclosures
Weighted average grant date fair value (in dollars per share)	$ 8.60	$ 6.90	$ 7.40
Options vested (in shares)	521,734
Total grant date fair value of options vested (in dollars)	4.5	5.5	9.8
Aggregate intrinsic value of options exercised (in dollars)	$ 1.0	$ 0.1	$ 0.1