Summary Of Significant Accounting Policies (Narrative) (Details) $ in Thousands, ft² in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) ft²	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) ft²	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Significant Accounting Policies [Line Items]
Square footage of operating properties (in square feet) | ft²	31.0		31.0
Accrued Rent, Accrued Contract Receivables and Accounts Receivable, net	$ 79,392		$ 79,392		$ 83,639
Allowance for credit loss	0		0
Other	2,925	$ 3,984	8,549	$ 10,494
Interest Rate Contract [Member] | Cash Flow Hedging [Member]
Significant Accounting Policies [Line Items]
Cash flow hedge gain (loss) to be amortized within 12 months	(900)		$ (900)
Tenant Base [Member] | Revenue Benchmark [Member]
Significant Accounting Policies [Line Items]
Concentrations of risk			2.70%
HOUSTON | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Significant Accounting Policies [Line Items]
Concentrations of risk			20.20%
OTHER PARTS OF TEXAS | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Significant Accounting Policies [Line Items]
Concentrations of risk			9.80%
FLORIDA | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Significant Accounting Policies [Line Items]
Concentrations of risk			20.50%
CALIFORNIA | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Significant Accounting Policies [Line Items]
Concentrations of risk			16.90%
COVID-19 [Member]
Significant Accounting Policies [Line Items]
Accrued Rent, Accrued Contract Receivables and Accounts Receivable, net	12,100		$ 12,100
Rent forgiveness	1,000		1,300
Adjustment to revenue related to potentially uncollectible revenues and disputed amounts	1,400		30,100
Straight Line Rent Receivables [Member]
Significant Accounting Policies [Line Items]
Adjustment to revenue related to potentially uncollectible revenues and disputed amounts	$ (300)		$ 12,100