The Company is the lessor for its residential and non-residential leases and these leases are accounted for as operating leases under the lease standard.

For the years ended December 31, 2021, 2020 and 2019, approximately 97%, 98% and 97%, respectively, of the Company’s total lease revenue is generated from residential apartment leases that are generally twelve months or less in length. The residential apartment leases may include lease income related to such items as utility recoveries, parking rent, storage rent and pet rent that the Company treats as a single lease component because the amenities cannot be leased on their own and the timing and pattern of revenue recognition are the same. The collection of lease payments at lease commencement is probable and therefore the Company subsequently recognizes lease income over the lease term on a straight-line basis. Residential leases are renewable upon consent of both parties on an annual or monthly basis.

For the years ended December 31, 2021, 2020 and 2019, approximately 3%, 2% and 3%, respectively, of the Company’s total lease revenue is generated by non-residential leases that are generally for terms ranging between five to ten years. The non-residential leases generally consist of ground floor retail spaces and master-leased parking garages that serve as additional amenities for our residents. The non-residential leases may include lease income related to such items as utility recoveries, parking rent and storage rent that the Company treats as a single lease component because the amenities cannot be leased on their own and the timing and pattern of

revenue recognition are the same. The collection of lease payments at lease commencement is probable and therefore the Company subsequently recognizes lease income over the lease term on a straight-line basis. Non-residential leases are renewable with market-based renewal options.

The Company elected the practical expedient to account for both its lease and non-lease components (specifically common area maintenance charges) as a single lease component under the lease standard.

The following table presents the lease income types relating to lease payments for residential and non-residential leases along with the total other rental income for the years ended December 31, 2021, 2020 and 2019 (amounts in thousands):

	Year Ended December 31, 2021								Year Ended December 31, 2020									Year Ended December 31, 2019
Income Type	Residential Leases			Non-Residential Leases		Total			Residential Leases			Non-Residential Leases			Total			Residential Leases		Non-Residential Leases			Total
Residential and non-residential rent	$	2,199,986		$	61,033	$	2,261,019		$	2,336,778		$	51,663		$	2,388,441		$	2,414,201	$	71,988		$	2,486,189
Utility recoveries (RUBS income) (1)		74,846			723		75,569			70,699			677			71,376			67,659		917			68,576
Parking rent		40,934			565		41,499			38,743			412			39,155			37,557		348			37,905
Other lease revenue (2)		(17,667	)		4,027		(13,640	)		(28,663	)		(5,519	)		(34,182	)		1,979		(820	)		1,159
Total lease revenue	$	2,298,099		$	66,348		2,364,447		$	2,417,557		$	47,233			2,464,790		$	2,521,396	$	72,433			2,593,829
Parking revenue							26,789									22,210								28,272
Other revenue							72,761									84,705								78,590
Total other rental income (3)							99,550									106,915								106,862
Rental income						$	2,463,997								$	2,571,705							$	2,700,691

The economic impact of the pandemic on a subset of our residents and tenants has led to elevated levels of bad debt, which was reduced, in part, by governmental rental assistance payments paid on their behalf. We continue to work with our residents and tenants on payment plans and collections and our bad debt allowance policies remain consistent from those existing prior to the pandemic.

The following table presents residential and non-residential accounts receivable and straight-line receivable balances for the Company’s properties as of December 31, 2021 and 2020 (amounts in thousands):

	Residential							Non-Residential
Balance Sheet (Other assets):	December 31, 2021				December 31, 2020			December 31, 2021			December 31, 2020
Resident/tenant accounts receivable balances	$	37,959			$	30,856		$	3,218		$	7,598
Allowance for doubtful accounts		(33,121	)			(24,021	)		(2,365	)		(6,527	)
Net receivable balances	$	4,838		(1)	$	6,835		$	853		$	1,071

Straight-line receivable balances	$	7,460			$	19,992		$	13,021		$	13,413

The following table presents residential bad debt for the Company’s properties for the years ended December 31, 2021, 2020 and 2019 (amounts in thousands):

Due to the impact of COVID-19 and the resulting economic impact on our non-residential tenants, we recognized a non-cash write-off of non-residential straight-line lease receivables of approximately $0.8 million and $13.2 million during the years ended December 31, 2021 and 2020, respectively. In addition, we reduced rental revenues by approximately $7.5 million and $7.3 million during the years ended December 31, 2021 and 2020, respectively, due to rent payment deferrals/abatements granted to our non-residential tenants.

The Company is the lessee under various corporate office and ground leases for which the Company recognizes right-of-use (“ROU”) assets and related lease liabilities. The following table presents the Company’s ROU assets and related lease liabilities as of December 31, 2021 and 2020 (amounts in thousands):

	2021		2020
Right-of-use assets:
Corporate office leases (operating)	$	36,897	$	39,203
Ground leases (finance)		97,575		57,584
Ground leases (operating)		340,241		402,500
Right-of-use assets	$	474,713	$	499,287
Lease liabilities:
Corporate office leases (operating)	$	37,760	$	40,470
Ground leases (finance)		69,479		23,350
Ground leases (operating)		205,096		265,310
Lease liabilities	$	312,335	$	329,130

The Company leases eight corporate offices with lease expiration dates ranging from 2022 through 2042 (inclusive of applicable extension options). See Note 15 for details on a corporate office lease with a related party.

The Company maintains long-term ground leases for 15 operating properties and one project under development with lease expiration dates ranging from 2042 through 2118 (inclusive of applicable purchase options). The Company owns the building and improvements. During the year ended December 31, 2021, the Company modified one ground lease that was previously classified as an operating lease. The Company now classifies this lease as a finance lease and reduced its lease liability and ROU asset due to remeasurement by approximately $11.3 million.

The following tables illustrate the quantitative disclosures for lessees as of and for the years ended December 31, 2021, 2020 and 2019 (amounts in thousands):

	Year Ended December 31, 2021		Year Ended December 31, 2020		Year Ended December 31, 2019
Lease cost:
Finance lease cost:
Amortization of right-of-use assets (capitalized)	$	351	$	—	$	—
Amortization of right-of-use assets (expensed)		1,391		—		—
Interest on lease liabilities (capitalized)		452		1,029		225
Interest on lease liabilities (expensed)		1,464		—		—
Operating lease cost:
Corporate office leases		3,581		3,747		3,937
Ground leases		18,338		22,102		22,198
Variable lease cost:
Corporate office leases		1,037		1,307		1,489
Ground leases		2,973		3,304		3,700
Total lease cost	$	29,587	$	31,489	$	31,549

	December 31, 2021			December 31, 2020			December 31, 2019
Other information:
Cash paid for amounts included in the measurement of lease liabilities:
Investing cash flows from finance leases	$	383		$	567		$	188
Financing cash flows from finance leases	$	1,898		$	—		$	34,734
Operating cash flows from operating leases:
Corporate office leases	$	5,016		$	5,296		$	5,494
Ground leases	$	14,682		$	16,552		$	16,837
ROU assets obtained in exchange for new finance lease liabilities	$	—		$	—		$	23,201
ROU assets obtained in exchange for new operating lease liabilities:
Corporate office leases	$	—		$	—		$	44,298
Ground leases	$	—		$	—		$	422,018
Weighted-average remaining lease term – finance leases	25.2 years			18.7 years			19.7 years
Weighted-average remaining lease term – operating leases:
Corporate office leases	16.8 years			17.4 years			18.1 years
Ground leases	61.8 years			55.3 years			56.2 years
Weighted-average discount rate – finance leases		2.8	%		3.0	%		3.0	%
Weighted-average discount rate – operating leases:
Corporate office leases		3.2	%		3.2	%		3.2	%
Ground leases		5.1	%		5.0	%		5.0	%

The following table summarizes the Company’s undiscounted cash flows for contractual obligations for minimum rent payments/receipts under operating and financing leases for the next five years and thereafter as of December 31, 2021:

(Payments)/Receipts Due by Year (in thousands)
	2022			2023			2024			2025			2026			Thereafter			Total
Finance Leases:
Minimum Rent Payments (a)	$	(2,463	)	$	(2,662	)	$	(2,880	)	$	(2,946	)	$	(2,959	)	$	(88,209	)	$	(102,119	)
Operating Leases:
Minimum Rent Payments (a)	$	(15,090	)	$	(14,998	)	$	(15,131	)	$	(14,957	)	$	(14,843	)	$	(831,456	)	$	(906,475	)
Minimum Rent Receipts (b)	$	58,561		$	56,754		$	51,295		$	45,091		$	37,283		$	135,922		$	384,906

The following table provides a reconciliation of lease liabilities from our undiscounted cash flows for minimum rent payments as of December 31, 2021 (amounts in thousands):