Fair Value Measurements (Quantitative Information About Significant Unobservable Inputs (Level 3) Used) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended		12 Months Ended
	Sep. 30, 2014		Dec. 31, 2013
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flows [Member] | Fixed-Rate Debt [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Input, Discount Rate	1.20%		1.30%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flows [Member] | Fixed-Rate Debt [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Input, Discount Rate	5.40%		7.40%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flows [Member] | Variable-Rate Debt [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Input, Discount Rate	0.80%		0.80%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flows [Member] | Variable-Rate Debt [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Input, Discount Rate	5.00%		5.00%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flows [Member] | Notes Receivable From Real Estate Joint Ventures And Partnerships [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Input, Discount Rate			2.70%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flows [Member] | Tax Increment Revenue Bonds [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Input, Discount Rate	7.50%		7.50%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flows [Member] | Tax Increment Revenue Bonds [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Input, Expected Future Growth Rate	1.00%		1.00%
Fair Value Input, Expected Future Inflation Rate	1.00%		1.00%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flows [Member] | Tax Increment Revenue Bonds [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Input, Expected Future Growth Rate	2.00%		2.00%
Fair Value Input, Expected Future Inflation Rate	2.00%		2.00%
Nonrecurring [Member] | Impaired Property [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Property			$ 11,876	[1]
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Impaired Property [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Property			8,576	[1]
Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Notes receivable from real estate joint ventures and partnerships			13,549
Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fixed-Rate Debt [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Debt	1,734,523		2,150,891
Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Variable-Rate Debt [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Debt	338,895		172,349
Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Tax Increment Revenue Bonds [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Investments	$ 25,392	[2]	$ 25,850	[2]

[1] In accordance with our policy of evaluating and recording impairments on the disposal of long-lived assets, property with a carrying amount of $14.3 million was written down to a fair value of $11.9 million, resulting in a loss of $2.4 million, which was included in earnings for the period. Management’s estimate of the fair value of these properties was determined using bona fide purchase offer for the Level 2 inputs. See the quantitative information about the significant unobservable inputs used for our Level 3 fair value measurements table below.

[2] At September 30, 2014 and December 31, 2013, the credit loss balance on our tax increment revenue bonds was $31.0 million.