We lease office, retail and storage space to tenants, primarily under non-cancellable operating leases which generally have terms ranging from five to fifteen years. Most of our leases provide tenants with extension options at either fixed or market rates and few of our leases provide tenants with options to terminate early, but such options generally impose an economic penalty on the tenant upon exercising. Rental revenue is recognized in accordance with ASC Topic 842, Leases, and includes (i) fixed payments of cash rents, which represent revenue each tenant pays in accordance with the terms of its respective lease and that is recognized on a straight-line basis over the non-cancellable term of the lease, and includes the effects of rent steps and rent abatements under the leases, (ii) variable payments of tenant reimbursements, which are recoveries of all or a portion of the operating expenses and real estate taxes of the property and are recognized in the same period as the expenses are incurred, (iii) amortization of acquired above and below-market leases, net and (iv) lease termination income.