Dividend (Details) (Dividend Declared [Member], USD $) In Millions, except Per Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	May 25, 2012
Dividend Declared [Member]
Class of Stock [Line Items]
Dividend, Common Stock Declared and Stock Option Holder Payment	$ (47.3)
Dividend, Common Stock Declared and Stock Option Holder Payment, Per Share	$ 0.30
Percentage of stock option payment paid immediately		50.00%
Percentage of dividend paid in 12 months		50.00%