The Company is the lessor for its residential and non-residential leases and these leases will continue to be accounted for as operating leases under the lease standard as described in Note 2.

For the years ended December 31, 2020 and 2019, approximately 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, storage 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, 2020 and 2019, approximately 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, 2020 and 2019 (amounts in thousands):

	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 and non-residential rent	$	2,336,778	$	51,663	$	2,388,441	$	2,414,201	$	71,988	$	2,486,189
Utility recoveries (RUBS income) (1)		70,699		677		71,376		67,659		917		68,576
Parking rent		38,743		412		39,155		37,557		348		37,905
Storage rent		3,674		84		3,758		3,745		71		3,816
Pet rent		11,457		—		11,457		11,617		—		11,617
Total lease revenue	$	2,461,351	$	52,836		2,514,187	$	2,534,779	$	73,324		2,608,103
Parking revenue						22,210						28,272
Other revenue						35,308						64,316
Total other rental income (2)						57,518						92,588
Rental income					$	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. We continue to work with our residents and tenants on payment plans and collections and our bad debt allowance policies remain consistent.

The following table presents residential and non-residential accounts receivable and straight-line receivable balances for the Company’s properties as of December 31, 2020 and 2019 (amounts in thousands):

	Residential							Non-Residential
Balance Sheet (Other assets):	December 31, 2020				December 31, 2019			December 31, 2020			December 31, 2019
Resident/tenant accounts receivable balances	$	30,856			$	4,040		$	7,598		$	1,766
Allowance for doubtful accounts		(24,021	)			(1,190	)		(6,527	)		(1,412	)
Net receivable balances	$	6,835		(1)	$	2,850		$	1,071		$	354

Straight-line receivable balances	$	19,992			$	1,841		$	13,413		$	26,450

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

Due to the impact of COVID-19 and the resulting economic impact on our non-residential tenants, rental revenues declined as a result of a non-cash write-off of non-residential straight-line lease receivables of $13.2 million during the year ended December 31, 2020. In addition, rental revenues declined by $7.3 million during the year ended December 31, 2020 as a result of 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 recognized ROU assets and related lease liabilities effective January 1, 2019. The following table presents the Company’s ROU assets and related lease liabilities as of December 31, 2020 and 2019 (amounts in thousands):

	2020		2019
Right-of-use assets:
Corporate office leases (operating)	$	39,203	$	41,596
Ground leases (finance)		57,584		57,982
Ground leases (operating)		402,500		413,196
Right-of-use assets	$	499,287	$	512,774
Lease liabilities:
Corporate office leases (operating)	$	40,470	$	43,105
Ground leases (finance)		23,350		23,239
Ground leases (operating)		265,310		264,990
Lease liabilities	$	329,130	$	331,334

As the standard requires the recognition of a liability for the lease obligation, discount rates are used to determine the net present value of the lease payments. The discount rate for the lease is the rate implicit in the lease or, if that rate cannot be readily determined, the incremental borrowing rate. As the Company does not know the amount of the lessors’ initial direct costs, it cannot readily determine the rate implicit in the lease and instead must apply the incremental borrowing rate. The Company has estimated the discount rate ranges of 3.3% to 3.9% for corporate office leases and 4.4% to 5.5% for ground leases at adoption. Since the Company’s credit backs the corporate office lease obligations and the lease terms are generally ten years or less, the discount rate range was estimated by using the Company’s borrowing rates for actual pricing data. The discount rate range for ground leases takes into account various factors, including the longer life of the ground leases, and was estimated by using the Company’s borrowing rates for actual pricing data through 30 years and other long-term market rates.

The Company leases nine corporate offices with lease expiration dates ranging from 2021 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 14 operating properties and two projects under development with lease expiration dates ranging from 2042 through 2118 (inclusive of applicable purchase options). The Company owns the building and improvements.

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

	Year Ended December 31, 2020		Year Ended December 31, 2019
Lease cost:
Finance lease cost:
Amortization of right-of-use assets	$	—	$	—
Interest on lease liabilities (capitalized)		1,029		225
Operating lease cost:
Corporate office leases		3,747		3,937
Ground leases		22,102		22,198
Variable lease cost:
Corporate office leases		1,307		1,489
Ground leases		3,304		3,700
Total lease cost	$	31,489	$	31,549

	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 (capitalized)	$	567		$	34,922
Operating cash flows from operating leases:
Corporate office leases	$	5,296		$	5,494
Ground leases	$	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 (1)	18.7 years			19.7 years
Weighted-average remaining lease term – operating leases:
Corporate office leases	17.4 years			18.1 years
Ground leases	55.3 years			56.2 years
Weighted-average discount rate – finance leases		3.0	%		3.0	%
Weighted-average discount rate – operating leases:
Corporate office leases		3.2	%		3.2	%
Ground leases		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, 2020:

(Payments)/Receipts Due by Year (in thousands)
	2021			2022			2023			2024			2025			Thereafter			Total
Finance Leases:
Minimum Rent Payments (a)	$	(578	)	$	(590	)	$	(601	)	$	(614	)	$	(626	)	$	(33,224	)	$	(36,233	)
Operating Leases:
Minimum Rent Payments (a)	$	(17,160	)	$	(16,906	)	$	(16,997	)	$	(17,329	)	$	(17,375	)	$	(954,108	)	$	(1,039,875	)
Minimum Rent Receipts (b)	$	59,430		$	54,656		$	51,091		$	45,166		$	38,847		$	126,732		$	375,922

The following table provides a reconciliation of lease liabilities from our undiscounted cash flows for minimum rent payments as of December 31, 2020 (amounts in thousands):