Real Estate - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) Building
Net gain on sales of real estate properties	$ 531,807	$ 447,637	$ 256,810
Net gain on sales of land parcels	$ 34,234	2,044	987
Net gain on sales of unconsolidated entities		$ 69,500
Non-cash asset impairment charge			$ 702
San Francisco [Member]
Number of buildings damaged due to fire | Building			1