The Company generally leases its investment rental property to established tenants in the industrial, healthcare, restaurant, office, retail, and other industries. At June 30, 2020, the Company had 615 real estate properties which were leased under leases that have been classified as operating leases and 11 that have been classified as direct financing leases. Of the 11 leases classified as direct financing leases, three include land portions which are accounted for as operating leases (see Revenue Recognition within Note 2). Substantially all leases have initial terms of 10 to 20 years. The Company’s leases generally provide for limited increases in rent as a result of fixed increases, increases in the CPI, or increases in the tenant’s sales volume. Generally, tenants are also required to pay all property taxes and assessments, substantially maintain the interior and exterior of the building, and maintain property and liability insurance coverage. The leases also typically provide for one or more multiple year renewal options, at the election of the tenant, and are subject to generally the same terms and conditions as the initial lease.

Rental property subject to non-cancelable operating leases with tenants was as follows:

(in thousands)	June 30, 2020			December 31, 2019
Land	$	545,984		$	548,911
Land improvements		276,542			275,470
Buildings and improvements		2,825,327			2,850,571
Equipment		11,873			11,492
		3,659,726			3,686,444
Less accumulated depreciation		(312,934	)		(271,044	)
	$	3,346,792		$	3,415,400

For the three months ended

June 30,

For the six months ended

June 30,

(in thousands)

2020

2019

2020

2019

Depreciation

23,560

19,532

47,075

38,285

Estimated lease payments to be received under non-cancelable operating leases with tenants at June 30, 2020 are as follows:

(in thousands)
Remainder of 2020	$	142,216
2021		289,046
2022		291,422
2023		294,357
2024		290,202
Thereafter		2,229,760
	$	3,537,003

Since lease renewal periods are exercisable at the option of the tenant, the above amounts only include future lease payments due during the initial lease terms. In addition, such amounts exclude any potential variable rent increases that are based on changes in the CPI or future variable rents which may be received under the leases based on a percentage of the tenant’s gross sales.

The Company’s net investment in direct financing leases was comprised of the following:

(in thousands)	June 30, 2020			December 31, 2019
Undiscounted estimated lease payments to be received	$	49,524		$	72,753
Estimated unguaranteed residual values		16,049			20,358
Unearned income		(34,424	)		(51,221	)
Reserve for credit losses		(196	)		—
Net investment in direct financing leases	$	30,953		$	41,890

Undiscounted estimated lease payments to be received under non-cancelable direct financing leases with tenants at June 30, 2020 are as follows:

(in thousands)
Remainder of 2020	$	1,622
2021		3,304
2022		3,368
2023		3,433
2024		3,493
Thereafter		34,304
	$	49,524

The above rental receipts do not include future lease payments for renewal periods, potential variable CPI rent increases, or variable percentage rent payments that may become due in future periods.

The following table summarizes amounts reported as Lease revenues, net on the Condensed Consolidated Statements of Income and Comprehensive Income (Loss):

	For the three months ended June 30,					For the six months ended June 30,
(in thousands)	2020			2019		2020			2019
Contractual rental amounts billed for operating leases	$	67,342		$	60,294	$	140,170		$	118,713
Adjustment to recognize contractual operating lease billings on a straight-line basis		8,276			5,269		9,941			10,440
Variable rental amounts earned		51			—		74			—
Adjustment to revenue recognized for uncollectible rental amounts billed		(1,190	)		—		(2,223	)		(440	)
Total operating lease rental revenues		74,479			65,563		147,962			128,713
Earned income from direct financing leases		855			1,004		1,842			2,009
Operating expenses billed to tenants		4,335			2,486		8,067			6,761
Other income from real estate transactions		702			—		731			—
Total Lease revenues, net	$	80,371		$	69,053	$	158,602		$	137,483