ALLOWANCE FOR DOUBTFUL ACCOUNTS	12 Months Ended
Dec. 31, 2017
ALLOWANCE FOR DOUBTFUL ACCOUNTS
ALLOWANCE FOR DOUBTFUL ACCOUNTS	NOTE 6—ALLOWANCE FOR DOUBTFUL ACCOUNTS At December 31, 2017 and 2016, there was no balance in the allowance for doubtful accounts. The Company records bad debt expense as a reduction of rental income and/or tenant reimbursements. The Company recorded bad debt expense of $291,000, $105,000 and $89,000 during 2017, 2016 and 2015, respectively. Such bad debt expense related to rental income and tenant reimbursements due from five tenants at properties that filed for Chapter 11 bankruptcy protection during such years. In relation to these tenants, the Company wrote off (i) $362,000, $7,000 and $89,000 of unbilled straight-line rent receivable as a reduction to rental income, (ii) $67,000, $0 and $124,000 of unamortized intangible lease assets and liabilities as an adjustment to rental income and (iii) $884,000, $0 and $380,000 of tenant origination costs as an increase to depreciation expense during 2017, 2016 and 2015, respectively. In 2017, the Company sold three of these properties, located in Greenwood Village, Colorado, Niles, Illinois and Ann Arbor, Michigan (see Note 5) and re-tenanted one property in Philadelphia, Pennsylvania. The Company has determined that no impairment charge is required with respect to the remaining property, which at December 31, 2017, had a net book value of $2,118,000.

NOTE 6—ALLOWANCE FOR DOUBTFUL ACCOUNTS

At December 31, 2017 and 2016, there was no balance in the allowance for doubtful accounts.

The Company records bad debt expense as a reduction of rental income and/or tenant reimbursements. The Company recorded bad debt expense of $291,000, $105,000 and $89,000 during 2017, 2016 and 2015, respectively. Such bad debt expense related to rental income and tenant reimbursements due from five tenants at properties that filed for Chapter 11 bankruptcy protection during such years. In relation to these tenants, the Company wrote off (i) $362,000, $7,000 and $89,000 of unbilled straight-line rent receivable as a reduction to rental income, (ii) $67,000, $0 and $124,000 of unamortized intangible lease assets and liabilities as an adjustment to rental income and (iii) $884,000, $0 and $380,000 of tenant origination costs as an increase to depreciation expense during 2017, 2016 and 2015, respectively. In 2017, the Company sold three of these properties, located in Greenwood Village, Colorado, Niles, Illinois and Ann Arbor, Michigan (see Note 5) and re-tenanted one property in Philadelphia, Pennsylvania. The Company has determined that no impairment charge is required with respect to the remaining property, which at December 31, 2017, had a net book value of $2,118,000.