Stockholders' Equity Narrative (Details) (Accelerated Share Repurchase Program, USD $) In Millions, except Per Share data, unless otherwise specified	0 Months Ended	1 Months Ended		9 Months Ended
	Oct. 01, 2014	Dec. 31, 2014	Aug. 31, 2014	Feb. 22, 2015	Jul. 31, 2014
Accelerated Share Repurchase Program
Class of Stock [Line Items]
Share repurchase program, authorized amount					$ 500.0
Payments For Accelerated Share Repurchase Program			$ 500.0
Stock to be repurchased and retired	8.6	1.3
Accelerated share repurchases, price paid per share				$ 50.12