The Company leases facilities and certain equipment under noncancelable operating leases that expire at various dates through February 2031. Under the terms of the facilities leases, the Company is required to pay its proportionate share of property taxes, insurance and normal maintenance costs.

In 2015, the Company entered into a master lease agreement giving the Company the ability to lease vehicles under operating leases with initial terms of 36 months from the date of delivery. In 2018, the lease agreement was terminated and a new master lease agreement was entered into with a new vendor giving the Company the ability to lease vehicles under operating leases with initial terms ranging from 12 to 50 months from the date of delivery.

The Company leases facilities and certain equipment under noncancelable operating leases with remaining lease terms of 1.0 year to 10.4 years, some of which include options to extend the lease for up to two five-year terms. These optional periods were not considered in the determination of the right-of-use asset or the lease liability as the Company did not consider it reasonably certain that it would exercise such options.

	Years Ended December 31,
	2020		2019		2018
Operating lease cost	$	6,917	$	5,155	$	4,503

Supplemental cash flow information related to the Company’s leases were as follows (in thousands):

	Years Ended December 31,
	2020		2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	4,480	$	4,841
Right-of-use assets obtained in exchange for operating lease obligations:		42,039		13,399

The balance sheet classification of the Company’s lease liabilities was as follows (in thousands):

	December 31, 2020		December 31, 2019
Operating lease liabilities
Current portion included in accrued liabilities	$	5,087	$	3,434
Operating lease liabilities		44,460		6,361
Total operating lease liabilities	$	49,547	$	9,795

	Operating Leases
Years ending December 31,
2021	$	5,284
2022		7,193
2023		6,635
2024		6,397
2025		5,922
Thereafter		29,762
Total lease payments		61,193
Less:
Imputed interest		(11,646	)
Total operating lease liabilities	$	49,547

Operating lease liabilities are based on the net present value of the remaining lease payments over the remaining lease term. In determining the present value of lease payments, the Company uses its incremental borrowing rate based on the information available at the lease commencement date. As of December 31, 2020, the weighted average remaining lease term is 9.4 years and the weighted average discount rate used to determine the operating lease liability was 4.7%.

In the fourth quarter of 2018, the Company entered into an agreement to lease the 4^th and 5^th floors of corporate office space in San Diego, California with total minimum lease payments of $50.4 million over an initial term of 10 years and 9 months. In February 2020, the Company entered into the first amendment to the lease agreement to lease the 2^nd floor of corporate office space in San Diego, California with total minimum lease payments of $25.3 million over an initial term of approximately 10 years and 7 months. In March 2020, the Company entered into the second amendment to the lease agreement which increased the total minimum lease payments of the original corporate office space to $51.4 million. During the three months ended September 30, 2020, the lease for the 4^th and 5^th floors of corporate office space commenced and the Company capitalized a right of use asset and related lease liability of $40.3 million. The operating lease for the additional corporate office space from the first amendment to the lease agreement is expected to commence in first quarter of 2021. In connection with this lease and its amendment agreements, the Company established a letter of credit for $3.1 million, which has automatic annual extensions and is fully secured by restricted cash.