Revenue Recognition - Base rentals are recognized on a straight-line basis over the term of the lease. Straight-line rent adjustments recorded in other assets were approximately $25.1 million and $20.8 million as of December 31, 2012 and 2011 , respectively. As a provision of a tenant lease, if we make a cash payment to the tenant for purposes other than funding the construction of landlord assets, we defer the amount of such payments as a lease incentive. We amortize lease incentives as a reduction of base rental revenue over the term of the lease. Substantially all leases contain provisions which provide additional rents based on tenants' sales volume ( percentage rentals ) and reimbursement of the tenants' share of advertising and promotion, common area maintenance, insurance and real estate tax expenses. Percentage rentals are recognized when specified targets that trigger the contingent rent are met. Expense reimbursements are recognized in the period the applicable expenses are incurred. Payments received from the early termination of leases are recognized as revenue from the time the payment is receivable until the tenant vacates the space. The values of the above and below market leases are amortized and recorded as either an increase (in the case of below market leases) or a decrease (in the case of above market leases) to rental income over the remaining term of the associated lease. If a tenant terminates its lease prior to the original contractual termination of the lease and no rental payments are being made on the lease, any unamortized balance of the related above or below market lease value will be written off.