Investments in Real Estate and Other Affiliates - Summarized Financial Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) condominium	Dec. 31, 2020 USD ($) condominium	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Balance Sheet
Total Assets	$ 9,581,694	$ 9,140,332
Total Liabilities	5,848,524	5,396,195
Total Equity	3,710,670	3,715,023	$ 3,332,988	$ 3,238,126
Income Statement
Revenues	1,427,901	699,489	1,300,539
Operating Income	241,872	(119,561)	150,310
Net income (loss)	48,924	(3,173)	74,295
The Summit
Balance Sheet
Total Assets	225,133	310,855
Total Liabilities	169,814	209,968
Total Equity	55,319	100,887
Income Statement
Revenues	302,174	148,822	120,337
Gross Margin	116,641	29,012	32,205
Net income (loss)	$ 95,604	$ 21,924	26,298
Number of units closed | condominium	46	29
110 North Wacker
Balance Sheet
Total Assets	$ 707,005	$ 634,274
Total Liabilities	515,665	415,452
Total Equity	191,340	218,822
Income Statement
Revenues	38,699	5,333	0
Operating Income	8,525	(3,148)	0
Net income (loss)	(36,556)	(8,236)	0
Other Investments
Balance Sheet
Total Assets	510,756	247,742
Total Liabilities	233,368	166,418
Total Equity	277,388	81,324
Income Statement
Revenues	36,964	36,450	42,778
Operating Income	20,305	17,100	16,085
Net income (loss)	$ 10,856	$ 11,220	$ 5,162