Summary Selected Quarterly Financial Data (unaudited) (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Summary Selected Quarterly Financial Data (Textual) [Abstract]
Deferred income tax benefit		$ 5.5
Change in accounting estimates reversal of expense			1.1	0.8
Investment losses related to prior year periods before tax	(0.2)	(0.6)
Investment losses related to prior year periods after tax	$ (0.1)	$ (0.4)