Fair Value Measurements (Schedule Of Fair Value Disclosures) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable from real estate joint ventures and partnerships	$ 84,142	$ 89,776
Tax increment revenue bonds	25,850	26,505
Fair Value [Member] | Fair Value Using Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable from real estate joint ventures and partnerships	85,897	93,572
Tax increment revenue bonds	25,850	26,505
Fixed-Rate Debt [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt	2,013,253	1,992,599
Fixed-Rate Debt [Member] | Fair Value [Member] | Fair Value Using Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt	2,055,495	2,094,122
Variable-Rate Debt [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt	280,645	211,431
Variable-Rate Debt [Member] | Fair Value [Member] | Fair Value Using Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt	$ 289,560	$ 223,759