Investments in and Advances to Joint Ventures - Condensed Combined Financial Information of Company's Unconsolidated Joint Venture Investments (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Condensed Combined Balance Sheets
Land	$ 962,872		$ 953,556
Buildings	3,533,242		3,488,499
Fixtures and tenant improvements	544,374		509,866
Total real estate rental property	5,040,488		4,951,921
Less: Accumulated depreciation	(1,536,248)		(1,427,057)
Real estate rental property, net	3,504,240		3,524,864
Construction in progress and land	42,143		37,467
Total real estate assets, net	3,546,383		3,562,331
Other assets, net	117,857		130,690
Total assets	4,052,293		4,108,284
Mortgage debt	241,561		249,260
Total liabilities	2,033,826		2,163,461
Accumulated equity	2,018,467	$ 2,017,031	1,944,823	$ 1,959,712	$ 1,959,804	$ 1,981,478
Total liabilities and equity	4,052,293		4,108,284
Company's share of accumulated equity	64,778		72,555
Basis differentials	5,273		1,644
Deferred development fees, net of portion related to the Company's interest	(1,156)		(1,277)
Amounts payable to the Company	3,789		4,375
Investments in and Advances to Joint Ventures, net	72,684		77,297
Unconsolidated Joint Ventures [Member]
Condensed Combined Balance Sheets
Land	428,167		441,412
Buildings	1,212,771		1,258,879
Fixtures and tenant improvements	138,876		137,663
Total real estate rental property	1,779,814		1,837,954
Less: Accumulated depreciation	(501,506)		(492,288)
Real estate rental property, net	1,278,308		1,345,666
Construction in progress and land	8,444		58,201
Total real estate assets, net	1,286,752		1,403,867
Cash and restricted cash	61,797		35,212
Receivables, net	19,513		25,719
Other assets, net	53,415		61,381
Total assets	1,421,477		1,526,179
Mortgage debt	996,968		1,029,579
Notes and accrued interest payable to the Company	3,789		4,375
Other liabilities	59,890		57,349
Total liabilities	1,060,647		1,091,303
Accumulated equity	360,830		434,876
Total liabilities and equity	$ 1,421,477		$ 1,526,179