Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Stockholders' Equity Note [Abstract]
Stock Repurchase Program, Authorized Amount	$ 100.0
Common Stock, Shares, Issued	220,436,378	220,255,676
Preferred Stock, Par or Stated Value Per Share	$ 1	$ 1
Stock Repurchase Program Expiration Date	Sep. 08, 2017
Stock Repurchased and Retired During Period, Shares	6,800,000
Payments for Repurchase of Equity	$ 61.5