Shareholders' Equity (Employee Plan) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for share-based compensation plans	6,000,000
Unrecognized compensation cost	12.9
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for share-based compensation plans	1,000,000
Minimum percent of salary employees can invest	1.00%
Maximum percent of salary employees can invest	10.00%
Purchase prices equal to fair market value	95.00%
Number of shares issued under Plan	20,350