	2021						2020						2019
	Owned		Managed		Total		Owned		Managed		Total		Owned		Managed		Total
Lease rental income - operating leases	$	577,946	$	54,652	$	632,598	$	469,109	$	58,175	$	527,284	$	470,722	$	96,227	$	566,949
Interest income on net investment in finance leases		82,659		—		82,659		30,121		—		30,121		15,356		—		15,356
Interest income on container leaseback financing receivable		21,380		—		21,380		17,243		—		17,243		10,313		—		10,313
Variable lease revenue		12,708		1,385		14,093		21,952		4,273		26,225		21,468		5,674		27,142
Total lease rental income	$	694,693	$	56,037	$	750,730	$	538,425	$	62,448	$	600,873	$	517,859	$	101,901	$	619,760

Variable lease revenue includes other charges set forth in the leases, such as handling fees, pick-up and drop-off charges and charges for damage protection plan.

For finance leases, the net selling gain (loss) recognized at lease commencement, representing the difference between the estimated fair value of containers placed on these leases and their net book value, in the amount of $2,610, $(144) and $(1,027) for the years ended December 31, 2021, 2020 and 2019, respectively, are included in “gain on sale of owned fleet containers, net” in the consolidated statements of operations.

The following is a schedule, by year, of future minimum lease payments receivable under the long-term leases for the owned and managed container fleet as of December 31, 2021:

	Owned		Managed		Total
Year ending December 31:
2022		446,284		29,946		476,230
2023		400,845		26,955		427,800
2024		332,978		23,508		356,486
2025		258,530		18,888		277,418
2026		187,451		13,976		201,427
2027 and thereafter		364,757		15,824		380,581
Total future minimum lease payments receivable	$	1,990,845	$	129,097	$	2,119,942

The Company’s container leaseback financing receivable pertains to containers purchased that were leased back to the seller-lessees through a sales-type leaseback arrangement that are accounted for as financing transactions.

The following table represents the components of the container leaseback financing receivable as of December 31, 2021 and 2020:

	2021			2020
Future minimum payments receivable	$	483,325		$	505,473
Less: unearned income		(129,065	)		(141,181	)
Container leaseback financing receivable (1)		354,260			364,292
Less: Allowance for credit losses		(113	)		(424	)
Container leaseback financing receivable, net	$	354,147		$	363,868
Amounts due within one year		30,317			27,076
Amounts due beyond one year		323,830			336,792
Container leaseback financing receivable, net	$	354,147		$	363,868

(1) One major customer represented 90.6% and 89.7% of the Company’s container leaseback financing receivable portfolio as of December 31, 2021 and 2020, respectively. As of December 31, 2020, one other customer represented 10.3% of the Company’s container leaseback financing receivable portfolio.

The following table represents the components of the net investment in finance leases as of December 31, 2021 and 2020:

	2021			2020
Future minimum lease payments receivable	$	2,558,339		$	1,216,086
Residual value of containers		16,532			12,601
Less: unearned income		(768,038	)		(347,394	)
Net investment in finance leases (1)	$	1,806,833		$	881,293
Less: Allowance for credit losses		(743	)		(1,333	)
Net investment in finance leases, net	$	1,806,090		$	879,960
Amounts due within one year	$	113,048		$	78,459
Amounts due beyond one year		1,693,042			801,501
Net investment in finance leases, net	$	1,806,090		$	879,960

(1) One major customer represented 85.1% and 80.1% of the Company’s finance lease portfolio as of December 31, 2021 and 2020, respectively. No other customer represented more than 10% of the Company’s finance leases portfolio in each of those periods.

The following is a schedule by year of future minimum lease payments receivable under container leaseback financing receivable and net investment in finance leases as of December 31, 2021:

Year ending December 31:	Container Leaseback Financing Receivable		Net Investment in Finance Leases		Total
2022	$	50,515	$	215,431	$	265,946
2023		50,514		205,192		255,706
2024		46,427		201,925		248,352
2025		39,015		196,225		235,240
2026		37,524		198,151		235,675
2027 and thereafter		259,330		1,541,415		1,800,745
Total future minimum lease payments receivable	$	483,325	$	2,558,339	$	3,041,664

Right-of-use (“ROU”) lease assets and lease liabilities are recognized for the Company’s office space leases at the commencement date based on the present value of lease payments over the lease term. The Company does not recognize a related ROU asset and lease liability for short-term leases having a lease term of twelve months or less. As of December 31, 2021 and 2020, ROU operating lease assets amounted to $8,988 and $10,331, respectively, which were reported in “other assets” in the consolidated balance sheets. As of December 31, 2021 and 2020, total lease liabilities amounted to $11,044 and $12,636, respectively, which were reported in “other liabilities” in the consolidated balance sheets. As of December 31, 2021, the weighted average discount rate was 4.75% and the weighted average remaining lease term was 4 years.

Operating lease expense is recognized on a straight-line basis over the lease term and is reported in “general and administrative expense” in the consolidated statements of operations. Rent expense and other information related to the Company's operating leases during 2021, 2020 and 2019 are as follows:

	2021		2020		2019
Operating lease cost	$	2,103	$	2,103	$	2,095
Short-term and variable lease cost		112		128		138
Total rent expense	$	2,215	$	2,231	$	2,233

Cash paid for amounts included in the measurement of lease liabilities	$	2,379	$	2,221	$	2,098

Future minimum lease payment obligations under the Company’s noncancelable operating leases at December 31, 2021 were as follows:

	Operating leasing
Year ending December 31:
2022		2,271
2023		2,417
2024		2,397
2025		2,130
2026		2,179
2027 and thereafter		935
Total minimum lease payments		12,329
Less imputed interest		(1,285	)
Total present value of operating lease liabilities	$	11,044