The majority of payments that we receive for our residential and commercial leases are fixed. We receive variable payments from our residents and commercial tenants primarily for utility and other expense reimbursements. For the three and nine months ended September 30, 2019, our total lease income was comprised of the following amounts for all operating leases (in thousands):

	Three Months Ended September 30, 2019		Nine Months Ended September 30, 2019
Fixed lease income	$	213,945	$	639,359
Variable lease income		15,005		42,814
Total lease income	$	228,950	$	682,173

In general, our commercial leases have options to extend for a certain period of time at the tenant’s option. Future minimum annual rental payments we will receive under commercial operating leases, excluding such extension options, are as follows (in thousands):

October 1, 2019 to December 31, 2019	$	7,200
2020		26,861
2021		23,391
2022		19,910
2023		16,081
Thereafter		65,583
Total	$	159,026

Generally, our residential leases do not provide extension options and, as of September 30, 2019, have an average remaining term of 10.3 months. Future minimum rental payments pursuant to residential leases are excluded from the table above due to their shorter term.

For leases in which we are the lessee, beginning in 2019, we recognize right of use assets and related lease liabilities on our consolidated balance sheets. Upon adoption of the accounting guidance for leases, we recognized right of use assets of $87.5 million, which are included in other assets on our condensed consolidated balance sheets. We also recognized the related lease liabilities of $79.7 million, which are included in accrued liabilities and other on our condensed consolidated balance sheets. We estimated the value of the lease liabilities using a discount rate equivalent to the rate we would pay on a secured borrowing with similar terms to the lease.

Substantially all of the payments under our ground and office leases are fixed. Rents for extension periods, when provided for in the lease, are generally adjusted to market value at the time the option is exercised; therefore, these extension periods were not included in our determination of the right of use asset and lease liability. For the three and nine months ended September 30, 2019, our total lease cost for ground leases was $1.3 million and $5.8 million, respectively, and for office leases was $1.1 million and $2.4 million, respectively.

As of September 30, 2019, the ground and office leases have weighted average remaining terms of 79.3 years and 8.5 years, respectively, and weighted average discount rates of 4.12% and 3.22%, respectively. Minimum annual rental payments under operating leases, reconciled to the lease liabilities included in accrued liabilities and other on our condensed consolidated balance sheets are as follows (in thousands):

	Office Lease Future Minimum Rent			Ground Lease Future Minimum Rent			Total Operating Lease Future Minimum Rent
October 1, 2019 to December 31, 2019	$	852		$	529		$	1,381
2020		2,806			2,350			5,156
2021		2,704			2,439			5,143
2022		2,561			2,492			5,053
2023		1,871			2,492			4,363
Thereafter		10,644			422,169			432,813
Total		21,438			432,471			453,909
Less: Discount		(3,091	)		(354,941	)		(358,032	)
Total lease liability	$	18,347		$	77,530		$	95,877