Segment Reporting - Revenues and Profit (loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Revenues	$ 24,307	$ 12,387	$ 33,527	$ 25,460
Profit (Loss)	14,238	(22,628)	(38,981)	30,105
Operating Segments
Segment Reporting Information [Line Items]
Revenues	33,463	54,558	73,335	235,174
Profit (Loss)	26,452	(12,457)	15,386	84,020
Corporate and Unallocated
Segment Reporting Information [Line Items]
Profit (Loss)	(10,749)	(14,602)	(27,044)	(30,867)
Valencia
Segment Reporting Information [Line Items]
Revenues	17,861	820
Valencia | Operating Segments
Segment Reporting Information [Line Items]
Revenues	17,861	820	18,657	2,435
Profit (Loss)	1,677	(4,261)	(3,117)	(8,345)
San Francisco
Segment Reporting Information [Line Items]
Revenues	172	972	1,147	2,065
San Francisco | Operating Segments
Segment Reporting Information [Line Items]
Revenues	172	972	1,147	2,065
Profit (Loss)	(2,466)	(4,465)	(5,558)	56,609
Great Park
Segment Reporting Information [Line Items]
Revenues	6,177	10,437	13,529	20,833
Profit (Loss)	(4,092)	(1,496)	(34,452)	7,948
Great Park | Operating Segments
Segment Reporting Information [Line Items]
Revenues	6,827	43,854	36,355	213,413
Profit (Loss)	(10,185)	(2,325)	(12,727)	37,943
Great Park | Removal of Results of Unconsolidated Entities
Segment Reporting Information [Line Items]
Revenues	(650)	(33,417)	(22,826)	(192,580)
Profit (Loss)	11,959	5,536	16,277	(31,575)
Commercial
Segment Reporting Information [Line Items]
Revenues	97	158	194	127
Commercial | Operating Segments
Segment Reporting Information [Line Items]
Revenues	8,603	8,912	17,176	17,261
Profit (Loss)	37,426	(1,406)	36,788	(2,187)
Gateway Commercial Venture
Segment Reporting Information [Line Items]
Profit (Loss)	27,997	(1,173)	27,446	(1,735)
Gateway Commercial Venture | Removal of Results of Unconsolidated Entities
Segment Reporting Information [Line Items]
Revenues	(8,506)	(8,754)	(16,982)	(17,134)
Profit (Loss)	$ (37,329)	$ 1,564	$ (36,594)	$ 2,314