Summary Of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2013 segment sqft foreign	Dec. 31, 2013 Retirement Plan [Member]	Dec. 31, 2013 Retirement Plan [Member] Minimum [Member]	Dec. 31, 2010 Retirement Plan [Member] Minimum [Member]	Dec. 31, 2013 Retirement Plan [Member] Maximum [Member]	Dec. 31, 2011 Supplemental Retirement Plans [Member] plans	Dec. 31, 2011 Supplemental Retirement Plans [Member] Minimum [Member]	Dec. 31, 2011 Supplemental Retirement Plans [Member] Maximum [Member]	Dec. 31, 2013 Supplemental Retirement Plan, Defined Contribution Plan [Member] Minimum [Member]	Dec. 31, 2013 Supplemental Retirement Plan, Defined Contribution Plan [Member] Maximum [Member]	Dec. 31, 2013 Supplemental Retirement Plan, Defined Contribution Plan [Member] New Balance Annual Addtions [Member]	Dec. 31, 2013 Supplemental Retirement Plan, Defined Contribution Plan [Member] New Balance Annual Addtions [Member] Minimum [Member]	Dec. 31, 2013 Supplemental Retirement Plan, Defined Contribution Plan [Member] New Balance Annual Addtions [Member] Maximum [Member]	Dec. 31, 2013 Supplemental Retirement Plan, Defined Contribution Plan [Member] Old Balance Annual Addtions [Member]	Dec. 31, 2013 Savings and Investment Plan, Defined Contribution Plan [Member]	Dec. 31, 2013 Restricted Shares [Member]	Dec. 31, 2011 Restricted Shares [Member]	Dec. 31, 2011 Restricted Shares [Member] Officer [Member]	Dec. 31, 2011 Share Options [Member]	Dec. 31, 2011 Share Options [Member] Non-Officer [Member]	Dec. 31, 2011 Share Options [Member] Officer [Member]	Dec. 31, 2013 Service-Based Awards [Member] Restricted Shares [Member]	Dec. 31, 2013 Market Based Awards [Member] Restricted Shares [Member]	Dec. 31, 2013 Market Based Awards [Member] Market-Based Awards Relative To FTSE NAREIT U.S. Shopping Center Index [Member]	Dec. 31, 2013 Market Based Awards [Member] Market-Based Awards Relative To Three-Year Absolute TSR	Dec. 31, 2013 Building [Member]	Dec. 31, 2013 Building [Member] Minimum [Member]	Dec. 31, 2013 Building [Member] Maximum [Member]	Dec. 31, 2013 Parking Lot Surfacing And Equipment [Member] Minimum [Member]	Dec. 31, 2013 Parking Lot Surfacing And Equipment [Member] Maximum [Member]	Dec. 31, 2013 Rental Revenues [Member] Tenant Base [Member]	Dec. 31, 2013 Net Operating Income [Member] Houston, Texas Geographic Concentration [Member]	Dec. 31, 2013 Net Operating Income [Member] Other Parts of Texas Geographic Concentration [Member]	Dec. 31, 2013 Revenues, Segment [Member]	Dec. 31, 2013 Net Operating Income, Segment [Member]	Dec. 31, 2013 Assets, Segment [Member]
Significant Accounting Policies [Line Items]
Date of establishment	1948
Square footage of operating properties	49,900,000
Concentrations of risk																															3.80%	19.10%	8.40%	10.00%	10.00%	10.00%
Real estate asset, estimated useful life																										40 years	18 years	40 years	10 years	20 years
Depreciation method, New Development	no depreciation is recorded on these assets until rent commences or no later than one year from the completion of major construction
Capitalization method, New Development	The capitalization of such costs ceases at the earlier of one year from the completion of major construction or when the property, or any completed portion, becomes available for occupancy.
Single purpose entity, ownership percentage	100.00%
Dividend distribution tax payment description	As long as we distribute at least 90% of the taxable income of the REIT (without regard to capital gains or the dividends paid deduction) to our shareholders as dividends, we will not be taxed on the portion of our income we distribute as dividends unless we have ineligible transactions.
Vesting period (years) for share options and awards																3 years		5 years		3 years	5 years	3 years	3 years
Percentage allocation of market based awards																								50.00%	50.00%
Share award price determination method																	restricted shares for officers and trust managers are granted at no purchase price		The grant price for our options is calculated as an average of the high and low of the quoted fair value of our common shares on the date of grant.
Maximum term of option award (years)																			10 years
Share award fair value method used																			The fair value of share options was estimated on the date of grant using the Black-Scholes option pricing method based on certain expected weighted average assumptions; including the dividend yield, the expected volatility, the expected life and the risk free interest rate.
Period of historical data used to estimate volatility (years)																			10 years
Defined benefit plan, service credit percentage			3.00%		5.00%
Defined benefit plan, interest credit rate		4.50%		2.05%		7.50%
Defined benefit plan, vesting period (years)		3 years					5 years	10 years
Number of retirement plans						2
Defined contribution plan, service credit percentage												3.00%	5.00%
Defined contribution plan, interest credit percentage											4.50%			7.50%
Defined contribution plan, vesting period									5 years	10 years					5 years
Defined contribution plan, interest credit percentage, inactive														December 31 90-day LIBOR rate plus .50%
Defined contribution plan, minimum annual contribution per employee, percent															1.00%
Defined contribution plan, maximum employee contribution, description															established annually by the IRS
Defined contribution plan, employer matched rate of employee contributions, percentage															50.00%
Defined contribution plan, employer matching contribution, percent															6.00%
Number of foreign operations	0
Number of reportable segments	1