Stock-Based Compensation Plans (Restricted Shares Granted) (Details) (USD $)	9 Months Ended
	Sep. 30, 2012
Grant Share Amount A [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Restricted share grants, Date of Grant	Jan. 03, 2012
Restricted share grants, Shares	272,153
Restricted share grants, Market Value Per Share	$ 15.80
Restricted share grants, vesting percentage	33.00%
Restricted share grants Vesting Period, in years	3 years
Grant Share Amount B [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Restricted share grants, Date of Grant	Jan. 03, 2012	[1]
Restricted share grants, vesting percentage	100.00%	[1]
Restricted stock, vesting date	January 1, 2015	[1]
Performance Share Units Granted	132,910	[1]
Performance Share Unit Market Value	$ 23.68	[1]
Grant Share Amount C [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Restricted share grants, Date of Grant	Jan. 03, 2012
Restricted share grants, Shares	1,958
Restricted share grants, Market Value Per Share	$ 15.80
Restricted share grants, vesting percentage	100.00%
Restricted stock, vesting date	January 1, 2014
Grant Share Amount D [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Restricted share grants, Date of Grant	Apr. 01, 2012
Restricted share grants, Shares	1,879
Restricted share grants, Market Value Per Share	$ 17.80
Restricted share grants, vesting percentage	100.00%
Restricted stock, vesting date	January 1, 2014
Grant Share Amount E [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Restricted share grants, Date of Grant	Jul. 02, 2012
Restricted share grants, Shares	1,885
Restricted share grants, Market Value Per Share	$ 16.41
Restricted share grants, vesting percentage	100.00%
Restricted stock, vesting date	January 1, 2014
Grant Share Amount F [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Restricted share grants, Date of Grant	Aug. 23, 2012
Restricted share grants, Shares	3,539
Restricted share grants, Market Value Per Share	$ 18.84
Restricted share grants, vesting percentage	20.00%
Restricted share grants Vesting Period, in years	5 years
Maximum [Member] | Grant Share Amount B [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Restricted share grants, vesting percentage	200.00%

[1] Reflects the grant of PSUs to certain of our executive officers. The estimated fair value of the PSUs on grant date was determined using a Monte Carlo simulation model. The PSUs provide for an award based on the performance of our common stock over a three-year period with the maximum award being 200% of the original awarded PSUs and the minimum amount being zero. The vested PSUs will be settled in an equivalent number of shares of our common stock unless the Compensation Committee of our Board of Directors elects to pay in cash. See Note 12 of 2011 Form 10-K.