Share-based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Expense [Abstract]
Share-based Compensation Expense	$ 14.6	$ 14.9	$ 15.8
Summary of nonvested shares [Roll Forward]
Maximum issuable shares under Stock Incentive Plan	19,000,000
Shares available for future grant under Stock Incentive Plan	4,100,000
Stock Options [Member]
Share-based Compensation Expense [Abstract]
Share-based Compensation Expense	2.4	2.3	2.7
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility, minimum (in hundredths)	63.20%	59.70%	61.80%
Expected volatility, maximum (in hundredths)	73.20%	78.00%	77.70%
Weighted-average volatility (in hundredths)	69.40%	62.10%	66.00%
Risk-free interest rate, minimum (in hundredths)	0.30%	0.40%	0.70%
Risk-free interest rate, maximum (in hundredths)	1.20%	2.60%	2.90%
Dividend yield (in hundredths)	2.20%	1.40%	0.90%
Weighted-average grant-date fair value per share of options granted	$ 4.31	$ 6.83	$ 11.05
Share based compensation estimated to be forfeited (in hundredths)	5.00%
Summary of changes in shares outstanding under all long-term incentive plans [Rollforward]
Number of options outstanding, beginning balance (in shares)	1,372,044
Number of options granted (in shares)	497,000
Number of options exercised (in shares)	0
Number of options canceled (in shares)	(49,662)
Number of options outstanding, ending balance (in shares)	1,819,382	1,372,044
Number of exercisable options (in shares)	1,058,629
Number of unvested options (in shares)	760,753
Number of unvested options that are expected to vest (in shares)	722,715
Weighted average exercise price per option, outstanding, beginning of period (dollars per share)	$ 16.48
Weighted average exercise price per option granted (dollars per share)	$ 9.03
Weighted average exercise price per option exercised (dollars per share)	$ 0
Weighted average exercise price per option canceled (dollars per share)	$ 15.78
Weighted average exercise price per option, outstanding, end of period (dollars per share)	$ 14.46	$ 16.48
Weighted average exercise price per exercisable option (dollars per share)	$ 16.48
Weighted average exercise price per unvested options (dollars per share)	$ 11.87
Weighted average exercise price per unvested options that expected to vest (dollars per share)	$ 11.87
Remaining average contractual life of options outstanding (in years)	6 years 5 months
Remaining average contractual life of options exercisable (in years)	5 years 0 months
Remaining average contractual life of unvested options (in years)	8 years 6 months
Remaining average contractual life of unvested options that are expected to vest (in years)	8 years 6 months
Aggregate intrinsic value of options outstanding, outstanding	0
Aggregate intrinsic value of options outstanding, exercisable	0
Aggregate intrinsic value of options outstanding, unvested	0
Aggregate intrinsic value of options outstanding, unvested and expected to vest	0
Summary of nonvested shares [Roll Forward]
Intrinsic value of options exercised	0	0.2	2.2
Amount of unrecognized compensation costs	0.7
Weighted average period of recognition (in years)	1 year 5 months
Maximum term of stock option awards (in number of years)	P10Y
Minimum vesting period for stock option awards (in number of months)	6 months
Restricted Stock [Member]
Share-based Compensation Expense [Abstract]
Share-based Compensation Expense	5.3	5.9	6.7
Summary of nonvested shares [Roll Forward]
Nonvested, beginning of period (in shares)	455,767
Granted (in shares)	528,060
Vested/restrictions lapsed/earned (in shares)	(577,245)
Canceled (in shares)	(8,469)
Nonvested, end of period (in shares)	398,113	455,767
Weighted average grant date fair value, nonvested, beginning of period (dollars per share)	$ 15.26
Weighted average grant date fair value, granted (dollars per share)	$ 8.78
Weighted average grant date fair value, vested/restrictions lapsed/earned (dollars per share)	$ 12.09
Weighted average grant date fair value, canceled (dollars per share)	$ 12.53
Weighted average grant date fair value, nonvested, end of period (dollars per share)	$ 11.33	$ 15.26
Fair value of shares vested/restrictions lapsed during the period	7.0	4.8	8.5
Amount of unrecognized compensation costs	2.1
Weighted average period of recognition (in years)	1 year 7 months
Restricted Stock Units Issued to Directors [Member]
Share-based Compensation Expense [Abstract]
Share-based Compensation Expense	0.9	0.9	0.8
Performance Share Awards [Member]
Share-based Compensation Expense [Abstract]
Share-based Compensation Expense	6.0	5.8	5.6
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Weighted-average volatility (in hundredths)	69.40%	89.00%	87.90%
Weighted-average volatility S&P MidCap 400 Index (in hundredths)	42.20%	52.40%	49.80%
Risk-free interest rate (in hundredths)	0.40%	1.00%	1.40%
Dividend yield (in hundredths)	2.20%	1.40%	0.90%
Summary of nonvested shares [Roll Forward]
Nonvested, beginning of period (in shares)	659,093
Granted (in shares)	579,000
Vested/restrictions lapsed/earned (in shares)	0
Canceled (in shares)	(295,780)
Nonvested, end of period (in shares)	942,313	659,093
Weighted average grant date fair value, nonvested, beginning of period (dollars per share)	$ 19.91
Weighted average grant date fair value, granted (dollars per share)	$ 9.89	$ 15.78	$ 25.61
Weighted average grant date fair value, vested/restrictions lapsed/earned (dollars per share)	$ 0.00
Weighted average grant date fair value, canceled (dollars per share)	$ 24.73
Weighted average grant date fair value, nonvested, end of period (dollars per share)	$ 12.24	$ 19.91
Amount of unrecognized compensation costs	$ 5.4
Weighted average period of recognition (in years)	1 year 7 months
Minimum [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected term (in years)	2 years 7 months	2 years 7 months	2 years 8 months
Maximum [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected term (in years)	6 years 3 months	6 years 3 months	6 years 3 months