Accounts payable, accrued expenses, and other liabilities

9 Months Ended

Sep. 30, 2021

Accounts Payable and Accrued Liabilities [Abstract]

Accounts payable, accrued expenses, and other liabilities

The following table summarizes the components of accounts payable, accrued expenses, and other liabilities as of September 30, 2021, and December 31, 2020 (in thousands):

	September 30, 2021			December 31, 2020
Accounts payable and accrued expenses	$	558,065	(1)	$	285,021
Accrued construction	412,000			333,271
Acquired below-market leases	358,203			288,075
Conditional asset retirement obligations	58,729			47,070
Deferred rent liabilities	12,324			4,495
Operating lease liability	371,538			345,750
Unearned rent and tenant security deposits	299,089			276,751
Other liabilities	79,502			89,399
Total	$	2,149,450		$	1,669,832

(1)Includes $185.2 million related to deferred purchase price obligations in connection with two acquisitions of real estate. We paid $25.2 million of this balance related to one of the acquisitions in October 2021.

As of September 30, 2021, and December 31, 2020, our conditional asset retirement obligations liability primarily consisted of the soil and groundwater remediation liabilities associated with certain of our properties. Some of our properties may contain asbestos or may be subjected to other hazardous or toxic substances, which, under certain conditions, requires remediation. We engage independent environmental consultants to conduct Phase I or similar environmental assessments at our properties. This type of assessment generally includes a site inspection, interviews, and a public records review; asbestos, lead-based paint, and mold surveys; subsurface sampling; and other testing. We recognize a liability for the fair value of a conditional asset retirement obligation (including asbestos) when the fair value of the liability can be reasonably estimated. In addition, environmental laws and regulations subject our tenants, and potentially us, to liability that may result from our tenants’ routine handling of hazardous substances and wastes as part of their operations at our properties. These assessments and investigations of our properties have not to date revealed any additional environmental liability we believe would have a material adverse effect on our business and financial statements or that would require additional disclosures or recognition in our consolidated financial statements.