note basis in reviewing any payment past due for over 90 days. Any outstanding amounts are written off against the reserve  allowance when all possible means of collection have been exhausted. Investment in an Unconsolidated Affiliate – NNN accounted for its investment in an unconsolidated affiliate under the equity  method of accounting. In September 2007, NNN entered into a joint venture, NNN Retail Properties Fund I LLC (the “NNN  Crow JV”) with an affiliate of Crow Holdings Realty Partners IV, L.P., which is accounted for under the equity method of  accounting. During September 2012, NNN Crow JV sold all of its assets and paid off its bank term loan as of December 31,  2012. Commercial Mortgage Residual Interests, at Fair Value – Commercial mortgage residual interests, classified as available for  sale, are reported at their market values with unrealized gains and losses reported as other comprehensive income in  stockholders’ equity. NNN recognizes the excess of all cash flows attributable to the commercial mortgage residual interests  estimated at the acquisition/transaction date over the initial investment (the accretable yield) as interest income over the life of  the beneficial interest using the effective yield method. Losses are considered other than temporary valuation impairments if  and when there has been a change in the timing or amount of estimated cash flows, exclusive of changes in interest rates, that  leads to a loss in value. Cash and Cash Equivalents – NNN considers all highly liquid investments with a maturity of three months or less when  purchased to be cash equivalents. Cash and cash equivalents consist of cash and money market accounts. Cash equivalents are  stated at cost plus accrued interest, which approximates fair value. Cash accounts maintained on behalf of NNN in demand deposits at commercial banks and money market funds may exceed  federally insured levels; however, NNN has not experienced any losses in such accounts. Valuation of Receivables – NNN estimates the collectibility of its accounts receivable related to rents, expense reimbursements  and other revenues. NNN analyzes accounts receivable and historical bad debt levels, customer credit-worthiness and current  economic trends when evaluating the adequacy of the allowance for doubtful accounts. In addition, tenants in bankruptcy are  analyzed and estimates are made in connection with the expected recovery of pre-petition and post-petition claims. Goodwill – Goodwill arises from business combinations and represents the excess of the cost of an acquired entity over the net  fair value amounts that were assigned to the assets acquired and the liabilities assumed. In accordance with the FASB guidance  included in  Goodwill , NNN performs impairment testing on goodwill by comparing fair value of its reporting units to carrying  amount annually. The Company has no goodwill recorded as of December 31, 2013 or 2012, respectively. Debt Costs – Debt costs incurred in connection with NNN’s $500,000,000 line of credit and mortgages payable have been  deferred and are being amortized over the term of the respective loan commitment using the straight-line method, which  approximates the effective interest method. Debt costs incurred in connection with the issuance of NNN’s notes payable have  been deferred and are being amortized to interest expense over the term of the respective debt obligation using the effective  interest method. Revenue Recognition – Rental revenues for non-development real estate assets are recognized when earned in accordance with  the FASB guidance included in  Leases,  based on the terms of the lease of the leased asset. Rental revenues for properties under  construction commence upon completion of construction of the leased asset and delivery of the leased asset to the tenant.  52