Commitments and Contingencies (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) condominium_tower	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) condominium_tower	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Jun. 14, 2018 individual_or_entity
Loss Contingencies [Line Items]
Number of individuals or entities on petition | individual_or_entity						500
Construction payables, Change			$ 6,622,000
Loss contingency accrual for estimated repair costs	$ 114,500,000		114,500,000
Outstanding letters of credit	11,500,000		11,500,000		$ 15,400,000
Amount of outstanding surety bonds	275,300,000		275,300,000		$ 200,100,000
Rent expense	$ 2,000,000.0	$ 2,500,000	$ 5,300,000	$ 6,700,000
Guarantor obligations, reserved percentage of residential units			20.00%
Guarantor obligations, number of open condominium towers | condominium_tower	3		3
Guarantor obligations, number of towers under construction | condominium_tower	2		2
Guarantee obligations | Downtown Columbia
Loss Contingencies [Line Items]
Loss contingency guaranteed amount limit	$ 1,000,000.0		$ 1,000,000.0