Stockholders' Equity and Accumulated Other Comprehensive Income (Loss) (Narrative) (Details) - USD ($) shares in Millions, $ in Millions	9 Months Ended	30 Months Ended	50 Months Ended
	Sep. 30, 2015	Jan. 31, 2014	Sep. 30, 2015
Stock Repurchase Program, Period in Force		3 years
Share Repurchase Plan [Member]
Stock Repurchase Program, Authorized Amount	$ 1,100.0		$ 1,100.0
Stock Repurchased and Retired During Period, Shares	4.2		28.6
Stock Repurchased and Retired During Period, Value	$ 166.3		$ 786.7
Stock Repurchase Program, Remaining Value Authorized to be Repurchased	$ 270.0		$ 270.0