We have various non-cancelable lease agreements for certain of our offices with original lease periods expiring between 2020 and 2032. Our lease terms may include options to extend or terminate the lease when it is reasonably certain we will exercise that option. Certain of the arrangements have free rent periods or escalating rent payment provisions. Leases with an initial term of twelve months or less are not recorded on the consolidated balance sheets. We recognize rent expense on a straight-line basis over the lease term. Additionally, we sublease certain operating leases to third parties primarily as a result of moving to a centralized corporate office in Santa Monica, California in 2018.

	Three Months Ended June 30,						Six Months Ended June 30,
	2020			2019			2020			2019
	(in thousands)
Operating lease expense	$	15,334		$	13,206		$	29,739		$	26,887
Sublease income		(793	)		(1,268	)		(1,535	)		(2,193	)
Total net lease costs	$	14,541		$	11,938		$	28,204		$	24,694

The weighted-average remaining lease term (in years) and discount rate related to the operating leases were as follows:

	Six Months Ended June 30,
	2020			2019
Weighted-average remaining lease term		7.7			7.1
Weighted-average discount rate		5.6	%		6.2	%

As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the lease commencement date to determine the present value of lease payments.

The present value of our operating lease liabilities as of June 30, 2020 were as follows:

	Operating Leases
	(in thousands)
Remainder of 2020	$	26,670
2021		65,428
2022		56,572
2023		52,415
2024		52,061
Thereafter		143,745
Total lease payments	$	396,891
Less: Imputed interest		(76,063	)
Present value of lease liabilities	$	320,828

As of June 30, 2020, we have additional operating leases for facilities that have not yet commenced with lease obligations of $18.6 million. These operating leases will commence between 2020 and 2021 with lease terms of greater than one years to five years. This table does not include lease payments that were not fixed at commencement or modification.

Cash payments included in the measurement of our operating lease liabilities were $17.2 million and $16.7 million for the three months ended June 30, 2020 and 2019, respectively, and $38.3 million and $33.2 million for the six months ended June 30, 2020 and 2019, respectively.

Lease liabilities arising from obtaining operating lease right-of-use assets were not material for the six months ended June 30, 2020 and 2019, respectively.