Mortgage and Other Indebtedness Derivative Instruments (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Fair Value, Net	$ (4,528)	$ (5,805)
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative, Number of Instruments Held	4
Notional Amount Outstanding, Intererst Rate Swap	111,881	113,885
Pay Fixed Receive Variable Swap One [Member]
Derivatives, Fair Value [Line Items]
Notional Amount Outstanding, Intererst Rate Swap	54,086
Amortized amount	48,337
Pay fixed receive variable swap Two [Member]
Derivatives, Fair Value [Line Items]
Notional Amount Outstanding, Intererst Rate Swap	33,863
Amortized amount	30,276
Pay fixed receive variable swap Three [Member]
Derivatives, Fair Value [Line Items]
Notional Amount Outstanding, Intererst Rate Swap	12,660
Amortized amount	11,313
Pay fixed receive variable swap Four [Member]
Derivatives, Fair Value [Line Items]
Notional Amount Outstanding, Intererst Rate Swap	11,272
Amortized amount	10,083
Interest Rate Cap [Member]
Derivatives, Fair Value [Line Items]
Derivative, Number of Instruments Held	1
Notional Amount Outstanding, Interest Rate Cap	123,125
Amortized amount	122,375
Cash Flow Hedging [Member] | Pay Fixed Receive Variable Swap One [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Designated Benchmark Interest Rate	1-month LIBOR
Strike Rate	2.149%
Fair Value, Net	(2,162)	(2,775)
Maturity Date	Apr. 30, 2016
Cash Flow Hedging [Member] | Pay fixed receive variable swap Two [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Designated Benchmark Interest Rate	1-month LIBOR
Strike Rate	2.187%
Fair Value, Net	(1,386)	(1,776)
Maturity Date	Apr. 30, 2016
Cash Flow Hedging [Member] | Pay fixed receive variable swap Three [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Designated Benchmark Interest Rate	1-month LIBOR
Strike Rate	2.142%
Fair Value, Net	(504)	(647)
Maturity Date	Apr. 30, 2016
Cash Flow Hedging [Member] | Pay fixed receive variable swap Four [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Designated Benchmark Interest Rate	1-month LIBOR
Strike Rate	2.236%
Fair Value, Net	(476)	(607)
Maturity Date	Apr. 30, 2016
Cash Flow Hedging [Member] | Interest Rate Cap [Member] | Intangible lease assets and other assets [Member]
Derivatives, Fair Value [Line Items]
Designated Benchmark Interest Rate	3-month LIBOR
Strike Rate	5.00%
Fair Value, Net	$ 0	$ 0
Maturity Date	Jan. 01, 2014