Investments in Unconsolidated Joint Ventures (Balance Sheets of the Unconsolidated Joint Ventures) (Details) - USD ($) $ in Thousands		Sep. 30, 2022	Dec. 31, 2021
ASSETS
Real estate and development in process, net		$ 19,427,344	$ 18,275,954
Total assets		23,726,691	22,365,258
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Mortgage and notes payable, net		3,271,157	3,267,914
Other Liabilities		417,255	391,441
Members’/Partners’ equity		6,155,618	5,834,020
Total liabilities and equity / capital		23,726,691	22,365,258
Carying value of the Company's investment in unconsolidated joint ventures		1,593,834	1,482,997
Right-of-use assets - finance leases		237,505	237,507
Right of use assets - operating leases		167,935	169,778
Lease liabilities - finance leases		248,092	244,421
Lease liabilities - operating leases		205,008	204,561
Unconsolidated Joint Ventures [Member]
ASSETS
Real estate and development in process, net	[1]	5,858,271	5,579,218
Other assets		655,549	586,470
Total assets		6,513,820	6,165,688
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Mortgage and notes payable, net		3,425,972	3,214,961
Other Liabilities	[2]	681,228	652,135
Members’/Partners’ equity		2,406,620	2,298,592
Total liabilities and equity / capital		6,513,820	6,165,688
Company's share of equity		1,180,507	1,104,175
Basis differentials	[3]	346,312	341,751
Carying value of the Company's investment in unconsolidated joint ventures	[4]	1,526,819	1,445,926
Right-of-use assets - finance leases		248,900	248,900
Right of use assets - operating leases		21,400	22,300
Lease liabilities - finance leases		383,000	385,500
Lease liabilities - operating leases		30,500	30,400
Unconsolidated Joint Ventures [Member]
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Other Liabilities		67,000	37,100
Colorado Center
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Basis differentials		302,539	304,776
Carying value of the Company's investment in unconsolidated joint ventures	[5]	234,271	231,479
Gateway Commons Complex [Member]
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Basis differentials		51,188	51,009
Carying value of the Company's investment in unconsolidated joint ventures	[5]	314,137	327,148
Dock 72
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Basis differentials		(48,753)	(50,051)
Carying value of the Company's investment in unconsolidated joint ventures	[5]	$ 26,947	$ 27,343

[1] At September 30, 2022 and December 31, 2021, this amount included right of use assets - finance leases totaling approximately $248.9 million. At September 30, 2022 and December 31, 2021, this amount included right of use assets - operating leases totaling approximately $21.4 million and $22.3 million, respectively.

[2] At September 30, 2022 and December 31, 2021, this amount included lease liabilities - finance leases totaling approximately $383.0 million and $385.5 million, respectively. At September 30, 2022 and December 31, 2021, this amount included lease liabilities - operating leases totaling approximately $30.5 million and $30.4 million, respectively.

[3] This amount represents the aggregate difference between the Company’s historical cost basis and the basis reflected at the joint venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials result from impairments of investments, acquisitions through joint ventures with no change in control and upon the transfer of assets that were previously owned by the Company into a joint venture. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the joint venture level. The majority of the Company’s basis differences are as follows: September 30, 2022December 31, 2021Property(in thousands)Colorado Center$302,539 $304,776 Gateway Commons51,188 51,009 Dock 72(48,753)(50,051) These basis differentials (excluding land) will be amortized over the remaining lives of the related assets and liabilities.

[4] Investments with deficit balances aggregating approximately $67.0 million and $37.1 million at September 30, 2022 and December 31, 2021, respectively, are reflected within Other Liabilities in the Company’s Consolidated Balance Sheets.

[5] Investments with deficit balances aggregating approximately $67.0 million and $37.1 million at September 30, 2022 and December 31, 2021, respectively, are included within Other Liabilities in the Company’s Consolidated Balance Sheets.