Commitments And Contingencies (Property, Plant And Equipment And Legal Matters) (Details) (USD $) In Millions, unless otherwise specified		12 Months Ended			9 Months Ended			1 Months Ended		3 Months Ended		1 Months Ended				9 Months Ended	12 Months Ended
	Jun. 30, 2011	Sep. 30, 2008 Repair Cost [Member] Archstone [Member]	Sep. 30, 2008 Lost Lease Payments [Member] Archstone [Member]	Sep. 30, 2008 Class Action Defense Fees [Member] Archstone [Member]	Jun. 30, 2011 Legal Matters [Member]	Jun. 30, 2010 Legal Matters [Member]	Mar. 31, 2011 Legal Matters [Member]	Sep. 30, 2010 Boynton [Member]	Jun. 30, 2009 Boynton [Member]	Sep. 30, 2010 Boynton [Member]	Apr. 30, 2011 Boynton [Member]	Sep. 30, 2007 Mainland Laboratory [Member]	Aug. 31, 2009 Fentress Families Trust [Member]	Jul. 31, 2009 Fentress Families Trust [Member]	Mar. 31, 2009 Fentress Families Trust [Member]	Jun. 30, 2011 Fentress Families Trust [Member]	Sep. 30, 2008 Archstone [Member]
Long term capital commitments on property, plant and equipment	$ 0.4
Legal fees					16.2	3.8
Constructive trust amount ordered by trial court					16.0						16.0
Court ordered judgment											16
Potential loss for unresolved matters					16.0		15.0
Verdict for damages								7.3	8.7
Loss contingency damages sought value		$ 36.0	$ 15.0	$ 7.0					$ 43.0			$ 23.0	$ 1,500.0		$ 1,800.0	$ 15.0	$ 7.0
Number of defendants															16
Number of buildings																	21
Number of plaintiffs									8	46				62	395