Employee Benefit Plans (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended					1 Months Ended	12 Months Ended							12 Months Ended	1 Months Ended						1 Months Ended		12 Months Ended			1 Months Ended
	Dec. 31, 2011 years	Dec. 31, 2010	Dec. 31, 2009	Jan. 03, 2012	Dec. 31, 2008	Jan. 31, 2012 2005 Incentive Plan [Member]	Dec. 31, 2011 2005 Incentive Plan [Member]	Dec. 31, 2011 1995 Incentive Plan [Member]	Dec. 31, 2011 2009 Incentive Plan [Member]	Dec. 31, 2010 2009 Incentive Plan [Member]	Dec. 31, 2009 2009 Incentive Plan [Member]	Jan. 31, 2012 2009 Incentive Plan [Member]	Dec. 31, 2011 Stock Options [Member] 2005 Incentive Plan [Member]	Dec. 31, 2011 Stock Options [Member] 1995 Incentive Plan [Member]	Jan. 31, 2012 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2011 Restricted Stock Units (RSUs) [Member] 2005 Incentive Plan [Member]	Dec. 31, 2011 Stock Option One [Member]	Dec. 31, 2011 Stock Option Two [Member]	Dec. 31, 2011 Stock Option Three [Member]	Dec. 31, 2011 Stock Option Four [Member]	Jan. 31, 2011 Performance Share Units (PSUs) [Member]	Jan. 31, 2012 Executive Officer [Member] 2005 Incentive Plan [Member]	Dec. 31, 2011 Executive Officer [Member] 2009 Incentive Plan [Member]	Dec. 31, 2010 Executive Officer [Member] 2009 Incentive Plan [Member]	Dec. 31, 2009 Executive Officer [Member] 2009 Incentive Plan [Member]	Jan. 31, 2012 Executive Officer [Member] Performance Share Units (PSUs) [Member]	Jan. 31, 2012 Non-Executive Employees [Member] Restricted Stock Units (RSUs) [Member]	Jan. 31, 2012 Maximum [Member] Performance Share Units (PSUs) [Member]	Jan. 31, 2012 Minimum [Member] Performance Share Units (PSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, employer subscription rate	50.00%
Share-based compensation, maximum employee subscription rate	5.00%
Deferred compensation plan expense	$ 1.4	$ 1.6	$ 1.5
Shares available for grant							920,748
Maximum percentage of common stock that can be granted	10.00%
Stock split	two-for-one stock split
Aggregate number of shares granted							6,000,000						2,000,000			4,000,000
Awards granted to employees typically vest (in percentage)						33.00%	20.00%	20.00%						33.00%	33.00%						100.00%
Awards vesting period, years						3	five	5
Forfeitures on restricted stock (in percentage)	17.00%
Stock options granted maximum exercise life, in years	10
Options outstanding, shares	192,800	432,918	501,318		521,654												98,000	14,000	28,000	52,800
Exercised, weighted average exercise price	$ 10.92	$ 10.52	$ 8.67														$ 8.57	$ 10.59	$ 10.92	$ 13.91
Weighted average remaining contractual life of stock options	1.4
Stock options compensation expense		0
Share based payment award value									5.2	10.2	14.7	4.2												6.0	8.1
Intrinsic value of stock options exercised	1.1	0.1	0.1
Intrinsic value of options exercisable	1.0	0.6	0.5
Restricted stock expense	8.4	9.0	9.4						7.9	8.6	3.7												6.5	6.9	2.6
Compensation cost of unvested restricted stock awards	23.4	29.7	21.8
Weighted average vesting period related to nonvested restricted stock	2.7
Restricted shares issued, shares																										132,910
Common stock performance awards percentage																												200.00%	0.00%
Restricted share grants, shares						132,910																					139,243
Market price per share of restricted share						$ 15.80									$ 15.80
Market value of restricted shares															2.2							2.1
Share-based payment award, method of measuring cost of award	The maximum amount payable under these share-based cash awards is twice the original targeted award and if the average price during the measurement period is less than 50% (75% for 2012 grants) of the base price, no payout will be made at the applicable anniversary date.
Liability long-term incentive compensation plan									8.5
Stock-based liability paid				$ 4.0