Property Acquired, Property Sold, Property Held For Sale, Property Held For And Under Development, And Property And Equipment (Narrative) (Details) In Millions, unless otherwise specified	0 Months Ended			3 Months Ended		6 Months Ended
	Feb. 21, 2012 USD ($) property acre	Feb. 21, 2012 AUD acre	Jan. 10, 2012 USD ($) acre	Jun. 30, 2012 USD ($)	Jun. 30, 2011 USD ($)	Jun. 30, 2012 USD ($)	Jun. 30, 2011 USD ($)	Jun. 30, 2012 Chief Executive Officer [Member]
Property, Plant and Equipment [Line Items]
Area of property acquired (acres)	1.1	1.1	202.0
Number of residential units			843
Payment to acquire property			$ 5.5
Ownership interest in property acquired								50.00%
Number of properties sold	3	3
Proceeds from the sale property	1.9	1.8
Depreciation expense for property and equipment				$ 4.0	$ 3.6	$ 7.5	$ 7.1