Stockholders' Equity and Accumulated Other Comprehensive Income (Loss) (Narrative) (Details) - USD ($) shares in Millions, $ in Millions	6 Months Ended	30 Months Ended	47 Months Ended
	Jun. 30, 2015	Jan. 31, 2014	Jun. 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	3.2		27.5
Stock Repurchased and Retired During Period, Value	$ 124.0		$ 744.3
Share Repurchase Plan (Remaining) [Member]
Stock Repurchase Program, Remaining Value Authorized to be Repurchased	$ 312.3		$ 312.3