Dispositions and Impairment

During the three months ended March 31, 2019 and 2018, the Company disposed of its interests in various properties for an aggregate gross disposition price of $79,300 and $62,675, respectively, and recognized aggregate gains on sales of properties of $20,957 and $22,774, respectively.

As of March 31, 2019, the Company had five properties classified as held for sale. As of December 31, 2018, the Company had two properties classified as held for sale. The properties were classified as held for sale because the properties were either under contract for sale and/or a sale of the property to a third party within the next 12 months was probable.

Assets and liabilities of held for sale properties as of March 31, 2019 and December 31, 2018 consisted of the following:



	March 31, 2019			December 31, 2018
Assets:
Real estate, at cost	$	39,680		$	63,639
Real estate, intangible assets	7,202			14,498
Accumulated depreciation and amortization	(21,590		)	(16,873		)
Rent receivable - deferred	742			2,439
Other	282			165
	$	26,316		$	63,868

Liabilities:
Accounts payable and other liabilities	$	239		$	42
Prepaid rent	226			344
	$	465		$	386

The Company assesses on a regular basis whether there are any indicators that the carrying value of its real estate assets may be impaired. Potential indicators may include an increase in vacancy at a property, tenant financial instability, change in the estimated holding period of the asset and the potential sale or transfer of the property in the near future. An asset is determined to be impaired if the asset's carrying value is in excess of its estimated fair value and the Company estimates that its cost will not be recovered. During the three months ended March 31, 2019 and 2018, the Company recognized aggregate impairment charges on real estate properties of $588 and $53,049, respectively. Included in the impairment charges recognized during the three months ended March 31, 2019 are impairment charges of $339 and $249 recognized on unencumbered and vacant retail properties in Watertown, New York and Albany, Georgia, respectively, which were held for sale at March 31, 2019. Included in the impairment charges recognized during the three months ended March 31, 2018, are impairment charges of $17,906 recognized on a vacant encumbered office property in Overland Park, Kansas, whose mortgage is currently in default, and $25,433 on an unencumbered office property in Memphis, Tennessee, which was sold in December 2018.