Description Of Business And Segment Reporting (Reconciliation To Net Income Attributable To Common Shareholders) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Segment operating income (loss)	$ (13,977)	$ (7,039)
Depreciation and amortization expense	(5,650)	(5,270)
General and administrative expense	(5,097)	(5,945)
Equity earnings of unconsolidated joint ventures	(50)	78
Gain (loss) on sale of assets	46,545
Other income (expense)	1,641	(218)
Income (loss) before income taxes	29,796	(8,968)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Segment operating income (loss)	(9,643)	(2,467)
Unallocated Corporate Expense [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization expense	(231)	(192)
General and administrative expense	(4,103)	(4,380)
Interest expense, net	$ (4,363)	$ (1,789)