Employee Benefit Plans (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended				108 Months Ended
	Jan. 31, 2014	Dec. 31, 2013 ShareBasedCompensationPlan		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013		Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Maximum Employer Subscription Rate	75.00%	50.00%
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate		5.00%				5.00%
401k plan cost		$ 1,700,000		$ 1,600,000	$ 1,400,000
Number Of Stock Plans		2
Maximum percetage of total shares of common stock issued and outstanding eligible to be granted to executives, selected management employees, and non employee members of board of directors		10.00%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized		4,300,000
Shares available for grant		6,600,000				6,600,000
Maximum excercise life		10 years
Forfeitures On Restricted Stock Percentage		7.00%
Forfeiture On Restricted Stock Period		5 years
Stock or Unit Option Plan Expense		0		0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value		500,000		1,300,000	1,100,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance		0		52,800	192,800	0		432,918
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value				400,000	1,000,000
Compensation cost related to restricted shares		8,800,000		7,700,000	8,400,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized		14,200,000		13,200,000	12,000,000	14,200,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms		1 year 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	73,609	257,797		482,340	571,163
Share-based Compensation Arrangement by Share-based Payment Award, Per Share Weighted Average Price of Shares Purchased	$ 23.18
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options	1,700,000
Stock Authorized Shares Employee Stock Purchase Plans		1,500,000
Available Shares Employee Stock Purchase Plan		1,300,000
Percentage Of Share Of Non Vested Stock Considered As Call Option		85.00%				85.00%
Percentage of share of non-vested stock considered as put-option		15.00%
Allocated Share-based Compensation Expense		800,000		300,000
Measurement Period		20 days
Deferred Compensation Arrangement with Individual, Cash Award Granted, Amount	8,900,000	8,400,000		4,200,000	5,200,000	8,400,000
Deferred Compensation Arrangement with Individual, Compensation Expense		9,100,000		8,700,000	7,900,000
Deferred Compensation Cash-based Arrangements, Liability, Current and Noncurrent		14,800,000		13,000,000		14,800,000
Deferred Compensation Arrangement with Individual, Distributions Paid	9,200,000	7,100,000		5,500,000	5,900,000	7,100,000
Performance Share Units Granted	73,609
Total awards under the 2009 plan		0				0
2005 Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		33.00%			20.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years	3 years		3 years	5 years
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		100.00%
Long-Term Incentive Cash Plan 2009 Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Measurement Period		30 days
Minimum percentage of average price during measurement period		75.00%
Long-Term Incentive Cash Plan 2010 Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum percentage of average price during measurement period		50.00%
Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred Compensation Arrangement with Individual, Compensation Expense		5,300,000		7,300,000	6,500,000
Deferred Compensation Cash-based Arrangements, Liability, Current and Noncurrent		$ 11,100,000		$ 11,700,000		$ 11,100,000
Maximum Shares As Incentive Options Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant		2,000,000				2,000,000
Grant Share Amount B [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		100.00%	[1]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		89,329	[1]
Share-based Compensation Arrangement by Share-based Payment Award, Per Share Weighted Average Price of Shares Purchased		$ 30.96	[1]			$ 30.96	[1]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Share Based Compensation Arrangement By Share Based Payment Award Vesting date		January 1, 2016	[1]
Maximum [Member] | Grant Share Amount B [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award percentage		200.00%
Minimum [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award percentage		0.00%

[1] Reflects the grant of performance share units (“PSUs”) to 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.