Stockholders' Equity and Accumulated Other Comprehensive Income (Loss) (Narrative) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended	30 Months Ended	35 Months Ended	38 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2014	Jan. 31, 2014	Dec. 31, 2016	Sep. 30, 2014
Stock Repurchase Program, Authorized Amount				$ 300.0	$ 300.0
Stock Repurchase Program, Period in Force				3 years
Stock Repurchased and Retired During Period, Shares			8.6	12.9		21.6
Stock Repurchased and Retired During Period, Value			262.6	257.1		519.7
Stock Repurchase Program, Remaining Value Authorized to be Repurchased			37.4
Accelerated Share Repurchases, Payment		$ 350.0
Accelerated Share Repurchases, Shares Repurchased	2.0	9.4
Accelerated Share Repurchases, Initial Price Paid Per Share		$ 29.69