Dispositions - Land Dispositions (Details) $ in Thousands	1 Months Ended		12 Months Ended
	Jun. 30, 2016 USD ($) a	Jan. 31, 2016 USD ($) a	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) a
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net gain (loss) on sales of land			$ 11,825	$ 449	$ (295)
Secured debt assumed by buyers in connection with land disposition			0	$ 0	$ 2,322
Disposal group, disposed of by sale [Member] | Plaza Yarrow Bay Properties [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net gain (loss) on sales of land			$ 11,800
Disposal group, disposed of by sale [Member] | Carlsbad Oaks - Lot 7 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gross Site Acreage (unaudited) | a		7.6
Sales Price		$ 4,500
Disposal group, disposed of by sale [Member] | Carlsbad Oaks - Lots 4 & 5 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gross Site Acreage (unaudited) | a	11.2
Sales Price	$ 6,000
Disposal group, disposed of by sale [Member] | Carlsbad Oaks - Lot 8 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gross Site Acreage (unaudited) | a	13.2
Sales Price	$ 8,900
Disposal group, disposed of by sale [Member] | Carlsbad Oaks - Lots 7, 4 & 5, 8 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gross Site Acreage (unaudited) | a					32.0
Sales Price					$ 19,400
Secured debt assumed by buyers in connection with land disposition					$ 2,300