Share-based Compensation Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 8,600,000	$ 12,100,000	$ 13,700,000
Income tax benefit from compensation cost	3,000,000	4,200,000	1,500,000
Weighted average exercise price [Abstract]
Outstanding, beginning of period (in dollars per share)	$ 60.50
Granted (in dollars per share)	$ 0
Exercised (in dollars per share)	$ 0
Forfeited or expired (in dollars per share)	$ 63.78
Outstanding, end of period (in dollars per share)	$ 58.48	$ 60.50
Shares subject to option [Roll Forward]
Outstanding, beginning of period (in shares)	1,420,500
Granted (in shares)	0	0	0
Exercised (in shares)	0	0	0
Forfeited or expired (in shares)	(542,200)
Outstanding, end of period (in shares)	878,300	1,420,500
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 43.70
Exercise price range, upper range limit (in dollars per share)	$ 68.20
Options exercisable (in shares)	878,300
Options exercisable, remaining average life (in years)	8 months 12 days
Options exercisable, weighted average exercise price (in dollars per share)	$ 58.48
Closing stock price at end of period (in dollars per share)	$ 2.66
Shares [Roll Forward]
Restricted stock outstanding at end of period (in shares)	3,100,000
$43.70 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding (in shares)	348,500
Options outstanding, remaining average life (in years)	1 month 6 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 43.70
$68.20 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options exercisable (in shares)	529,800
Options exercisable, remaining average life (in years)	1 year 1 month 6 days
Options exercisable, weighted average exercise price (in dollars per share)	$ 68.20
Stock Options [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Aggregate intrinsic value of options outstanding	0
Aggregate intrinsic value of options exercisable	0
Restricted Stock [Member]
Weighted average grant date fair market value [Abstract]
Restricted stock outstanding at end of period (in dollars per share)	$ 12.88
Granted (in dollars per share)	$ 3.97	$ 8.94	$ 6.82
Vested (in dollars per share)	$ 7.62
Forfeited (in dollars per share)	$ 58.24
Restricted stock outstanding at end of period (in dollars per share)	$ 7.08	$ 12.88
Shares [Roll Forward]
Restricted stock outstanding at beginning of period (in shares)	2,945,762
Granted (in shares)	1,810,445
Vested (in shares)	(1,470,965)
Forfeited (in shares)	(207,660)
Restricted stock outstanding at end of period (in shares)	3,077,582	2,945,762
Additional disclosures [Abstract]
Restricted stock, performance shares (in shares)	2,300,000
Restricted stock, time vested shares (in shares)	800,000
Total fair value of restricted stock vested	6,900,000	14,900,000	8,500,000
Unrecognized compensation cost	8,800,000
Unrecognized compensation cost, performance shares	7,500,000
Unrecognized compensation cost, time vested shares	1,300,000
Weighted-average period for recognition of compensation cost	1 year 3 months 18 days
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	5 years
2002 Plan [Member] | Restricted Stock Units (RSUs) [Member] | Cash Settled Award [Member]
Weighted average grant date fair market value [Abstract]
Granted (in dollars per share)		$ 8.94
Shares [Roll Forward]
Granted (in shares)		449,350
Vested (in shares)	147,968
Forfeited (in shares)	1,200	5,400
Restricted stock outstanding at end of period (in shares)	294,782
Additional disclosures [Abstract]
Unrecognized compensation cost	400,000
Cash payments for vested shares	$ 600,000
Weighted-average period for recognition of compensation cost	1 year 1 month 6 days
2011 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares can be awarded under the plan (in shares)	7,000,000
Additional disclosures [Abstract]
Shares available for future grants (in shares)	5,200,000