Earnings Per Share (Narrative) (Details) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Earnings Per Share [Abstract]
Weighted average unvested shares outstanding	0.3	0.3	0.3	0.3
Anti-dilutive stock options excluded from dilutive earnings per share calculation	0	0.1	0	0.1
Cumulative convertible preferred share, dividend rate	5.417%	5.417%	5.417%	5.417%	5.417%