Federal Income Tax Considerations (Schedule Of Income Tax (Benefit) Provision) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Income Tax Note [Line Items]
Federal income tax benefit of taxable REIT subsidiary	$ (1,437)	[1]	$ (916)	[1]	$ (1,181)	[1]
Texas franchise tax	1,784	[2]	1,373	[2]	1,422	[2]
Total	$ 347		$ 457		$ 241

[1] All periods presented are open for examination by the IRS.

[2] For all periods presented, amounts include the effects that are reported in discontinued operations. See Note 15 for additional information.