In December 2007, we closed the sale of our facility and associated real property for a purchase price of $109.0 million. Concurrent with the sale, we retired the entire $47.7 million in mortgage debt previously outstanding with respect to the facility and associated real property and received cash of $61.0 million, net of transaction costs and debt retirement. The ultimate result of this real estate sale was a net deferred gain of $39.1 million, of which the remaining balance was $8.0 million as of December 31, 2018, and which we recognized as a cumulative-effect adjustment to equity upon adoption of Topic 842 on January 1, 2019.

Upon the closing of the sale of the facility and associated real property, we entered into an agreement (original lease) whereby we leased back our corporate headquarters, comprised of two buildings located in San Diego, California, for an initial term of 12 years. In 2008 through 2011, we entered into a series of subsequent amendments to the original lease, whereby we vacated a building and continued to occupy one building.

In June 2017, we entered into an amendment to extend the current term of the original lease through December 31, 2029. Under the terms of the amendment, we will continue to pay base annual rent (subject to an annual fixed percentage increase), property taxes, and other normal and necessary expenses, such as utilities, repairs, and maintenance. Certain incentives were included in the lease, including $13.1 million in tenant improvement allowances and three months of rent abatement. In lieu of a cash security deposit, Wells Fargo Bank, N.A. (Wells Fargo) issued a $3.0 million letter of credit on our behalf, which is secured by a deposit of equal amount with the same bank. We have the right to extend the lease for 2 consecutive 10-year terms and a right of first offer for future rental of adjacent office space owned by the landlord. At commencement of the lease, we were not reasonably certain to exercise either of the two 10-year extension options contained within the lease. As such, these options were not recognized as part of the associated operating lease ROU asset or liability.

In May 2018, we entered into an agreement to lease 44,718 square feet of office space in San Diego, California, which commenced on July 1, 2018, for a term of 10 years and 10 months. Under the terms of the lease, we will pay base annual rent (subject to an annual fixed percentage increase), plus property taxes, and other normal and necessary expenses, such as utilities, repairs, and maintenance. Certain incentives were included in the lease, including $4.2 million in tenant improvement allowances and twelve months of rent abatement. In lieu of a cash security deposit, Wells Fargo issued a $1.0 million letter of credit on our behalf, which is secured by a deposit of equal amount with the same bank. We do not have the right to extend the lease or right of first offer for future rental of adjacent office space owned by the landlord.

In the first quarter of 2019, our operating lease cost was $1.9 million and cash paid for amounts included in the measurement of lease liabilities for operating cash flows from operating leases was $1.6 million. As of March 31, 2019, we reported operating lease ROU assets and operating lease liabilities of $49.3 million and $70.4 million, respectively. Further, as of March 31, 2019, our operating leases had a weighted average remaining lease term of 10.57 years and a weighted average discount rate of 6.65%.

At March 31, 2019, the minimum lease payments for our operating lease liabilities were as follows:

(in thousands)	Operating Leases
Year Ending December 31,
2019 (9 months remaining)	$	5,777
2020		8,399
2021		8,624
2022		8,888
2023		9,160
Thereafter		59,462
Total operating lease payments		100,310
Less accreted interest		(29,896	)
Total operating lease liabilities		70,414
Less current operating lease liabilities		(3,267	)
Noncurrent operating lease liabilities	$	67,147