Common Stock Plans (Stock Options, Textual) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Performance share awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 4,000,000	$ 0	$ 0
Tax benefit related to stock-based compensation	1,500,000
Costs not recognized	5,500,000
Period for recognition	1 year 5 months 26 days
Stock options | Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	3,600,000	7,000,000	5,600,000
Tax benefit related to stock-based compensation	1,400,000	2,600,000	2,100,000
Intrinsic value of stock options exercised during period	15,700,000
Cash received from exercise of stock options	17,800,000
Intrinsic value for outstanding options	23,500,000
Intrinsic value for exercisable options	14,900,000
Fair value of vested options	5,800,000
Unrecognized compensation cost	500,000
Stock Appreciation Rights | Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of stock options exercised during period	8,500,000
Cash paid for settlement of stock appreciation rights	$ 5,800,000