Segment Information (Narrative) (Details)	6 Months Ended		9 Months Ended
	Dec. 31, 2010	Jun. 30, 2010	Sep. 30, 2011
Segment Information [Abstract]
Internally allocated interest costs, pre tax rate	6.50%	7.15%	6.25%
Capital structure assumption, debt portion			50
Capital structure assumption, equity portion			50