Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal From time to time, we are party to various lawsuits, claims and legal proceedings that arise in the ordinary course of business. We are not currently a party to any legal proceedings that we believe would reasonably be expected to have a material adverse effect on our business, financial condition or results of operations. Environmental We will generally perform environmental site assessments at properties we are considering acquiring. After the acquisition of such properties, we continue to monitor the properties for the presence of hazardous or toxic substances. From time to time, we acquire properties with known adverse environmental conditions. If at the time of acquisition, losses associated with environmental remediation obligations are probable and can be reasonably estimated, we record a liability. On February 25, 2014, we acquired the property located at West 228th Street. Before purchasing the property during the due diligence phase, we engaged a third-party environmental consultant to perform various environmental site assessments to determine the presence of any environmental contaminants that might warrant remediation efforts. Based on their investigation, they determined that hazardous substances existed at the property and that additional assessment and remediation work would likely be required to satisfy regulatory requirements. The total remediation costs were estimated to be $1.3 million, which includes remediation, processing and oversight costs. To address the estimated costs associated with the environmental issues at the West 228th Street property, we entered into an Environmental Holdback Escrow Agreement (the “Holdback Agreement”) with the former owner, whereby $1.4 million was placed into an escrow account to be used to pay remediation costs. To fund the $1.4 million, the escrow holder withheld $1.3 million of the purchase price, which would have otherwise been paid to the seller at closing, and the Company funded an additional $0.1 million. According to the Holdback Agreement, the seller has no liability or responsibility to pay for remediation costs in excess of $1.3 million. As of March 31, 2020 and December 31, 2019, we had a $0.6 million and $0.6 million contingent liability recorded in our consolidated balance sheets included in the line item “Accounts payable and accrued expenses,” reflecting the estimated remaining cost to remediate environmental liabilities at West 228th Street that existed prior to the acquisition date. As of March 31, 2020 and December 31, 2019, we also had a $0.6 million and $0.6 million corresponding indemnification asset recorded in our consolidated balance sheets included in the line item “Other assets,” reflecting the estimated costs we expect the former owner to cover pursuant to the Holdback Agreement. We expect that the resolution of the environmental matters relating to the above will not have a material impact on our consolidated financial condition, results of operations or cash flows. However, we cannot assure you that we have identified all environmental liabilities at our properties, that all necessary remediation actions have been or will be undertaken at our properties or that we will be indemnified, in full or at all, in the event that such environmental liabilities arise. Furthermore, we cannot assure you that future changes to environmental laws or regulations and their application will not give rise to loss contingencies for future environmental remediation. Tenant and Construction Related Commitments As of March 31, 2020, we had commitments of approximately $38.9 million for tenant improvement and construction work under the terms of leases with certain of our tenants and contractual agreements with our construction vendors. Concentrations of Credit Risk We have deposited cash with financial institutions that are insured by the Federal Deposit Insurance Corporation up to $250,000 per institution. Although we have deposits at institutions in excess of federally insured limits as of March 31, 2020, we do not believe we are exposed to significant credit risk due to the financial position of the institutions in which those deposits are held. Concentration of Properties in Southern California As of March 31, 2020, all of our properties are located in the Southern California infill markets. The ability of the tenants to honor the terms of their respective leases is dependent upon the economic, regulatory and social factors affecting the markets in which the tenants operate and other conditions, including the impact of the outbreak of the novel coronavirus (“COVID-19”), which was declared a pandemic in March 2020 by the World Health Organization, and related state and local government reactions. All of our properties are concentrated in Southern California, and the state of California and certain cities, including where we own properties, have reacted to the COVID-19 pandemic by instituting quarantines, restrictions on travel, “shelter in place” rules, restrictions on types of business that may continue to operate and/or restrictions on types of construction projects that may continue as well as moratoriums on commercial tenant evictions and provisions enabling commercial tenants to defer rent. We cannot predict when restrictions currently in place will expire. Additionally, in March 2020, the Governor of California issued Executive Order N-28-20, authorizing local municipalities to impose limitations on commercial evictions for nonpayment of rent for tenants impacted by COVID-19. In response to this Executive Order, most municipalities in Southern California have, in turn, mandated a moratorium on all commercial evictions and have given tenants impacted by COVID-19 the unilateral right to defer rent while the emergency “shelter in place” orders are in effect, with repayment generally within three to six months after the end of the local emergency “shelter in place” or similar order. While we did not incur significant disruptions from the COVID-19 pandemic during the three months ended March 31, 2020, we are currently unable to predict the impact that the COVID-19 pandemic will have on our tenants, including the number of tenants that will take advantage of the relief provided by the local government mandates authorizing the deferral of rent, and as a result, the impact on our business and results of operations. Tenant Concentration During the three months ended March 31, 2020, no single tenant accounted for more than 5% of our total consolidated rental income.