Organization And Significant Accounting Policies (Narrative) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012 Y Room Property	Sep. 30, 2011 Y	Sep. 30, 2012 Y Room Property	Sep. 30, 2011 Y	Dec. 31, 2011
Real Estate Properties [Line Items]
Number of units in real estate property	22,218		22,218
Number of communities held in unconsolidated entities	60		60
Common stock, shares outstanding	54,413		54,413		52,988
Ownership interest percentage in Operating Partnership	99.70%	99.70%	99.70%	99.70%
Common units held by persons other than the Company	143		143
Noncontrolling interest, ownership percentage by noncontrolling owners	0.003%		0.003%
Revenue recognized lease (in years)
Development or construction costs	$ 973	$ 879	$ 2,692	$ 1,975
Buildings And Components [Member]
Real Estate Properties [Line Items]
Estimated useful life (in years)			40 years
Other Building And Land Improvements [Member]
Real Estate Properties [Line Items]
Estimated useful life (in years)			20 years
Furniture, Fixtures And Equipment [Member] | Minimum [Member]
Real Estate Properties [Line Items]
Estimated useful life (in years)			5 years
Furniture, Fixtures And Equipment [Member] | Maximum [Member]
Real Estate Properties [Line Items]
Estimated useful life (in years)			10 years
Atlanta, Georgia [Member]
Real Estate Properties [Line Items]
Concentration of location for communities, percentage	32.80%		32.80%
Dallas, Texas [Member]
Real Estate Properties [Line Items]
Concentration of location for communities, percentage	23.40%		23.40%
Washington, D.C. [Member]
Real Estate Properties [Line Items]
Concentration of location for communities, percentage	12.70%		12.70%
Tampa, Florida [Member]
Real Estate Properties [Line Items]
Concentration of location for communities, percentage	10.50%		10.50%
Unconsolidated Properties [Member]
Real Estate Properties [Line Items]
Number of units in real estate property	1,471		1,471
Under Development [Member]
Real Estate Properties [Line Items]
Number of units in real estate property	2,046		2,046
Cost Capitalization [Member]
Real Estate Properties [Line Items]
Weighted average borrowing costs, percentage	0.055%	6.00%	0.055%	6.00%