The Company leases facilities and certain equipment under noncancelable operating leases with remaining lease terms of 1.3 years to 10.7 years, some of which include options to extend for up to two five-year terms. These optional periods were not considered in the determination of the right-of-use assets or the lease liabilities as the Company did not consider them reasonably certain that it would exercise such options.

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
Operating lease cost	$	1,835	$	1,298	$	4,750	$	3,844

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

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	1,128	$	1,240	$	3,710	$	3,600
Right-of-use assets obtained in exchange for operating lease obligations:		41,190		864		41,571		12,815

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

	September 30, 2020		December 31, 2019
Operating lease liabilities
Current portion included in accrued liabilities	$	3,857	$	3,434
Operating lease liabilities		45,343		6,361
Total operating lease liabilities	$	49,200	$	9,795

	Operating Leases
Remainder of 2020	$	732
Years ending December 31,
2021		5,134
2022		7,043
2023		6,485
2024		6,260
Thereafter		35,684
Total lease payments		61,338
Less:
Imputed interest		(12,138	)
Total operating lease liabilities	$	49,200

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 September 30, 2020, the weighted average remaining lease term is 9.7 years and the weighted average discount rate used to determine the operating lease liabilities 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 the 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.