Stock Repurchases (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stockholders' Equity Note [Abstract]
Authorized amount for share repurchase		$ 300.0	$ 700.0
Payments Related to Tax Withholding for Share-based Compensation	12.0	7.8	3.3
Treasury stock purchases, shares	1.7	1.1
Remaining authorized amount for share repurchase	246.2
Payments for Repurchase of Common Stock	125.0	50.1	119.7
Accelerated Share Repurchases, Settlement (Payment) or Receipt	$ 0.2
Shares Paid for Tax Withholding for Share Based Compensation	0.2	0.2