Dispositions and Assets Held for Sale

We periodically sell properties for various reasons, including favorable market conditions, the exercise of tenant purchase options or reduction of concentrations (e.g., property type, relationship or geography). At September 30, 2018, 60 triple-net, 16 seniors housing operating and three outpatient medical properties with an aggregate real estate balance of $619,141,000 were classified as held for sale. During the nine months ended September 30, 2018, we recorded impairment charges of $39,557,000 on certain held for sale properties for which the carrying values exceeded the fair values, less estimated costs to sell if applicable. The following is a summary of our real property disposition activity for the periods presented (in thousands):



	Nine Months Ended
	September 30, 2018		September 30, 2017
Real estate dispositions:
Triple-net	$	604,480	$	899,104
Seniors housing operating	2,200		16,206
Outpatient medical	223,069		12,202
Total dispositions	829,749		927,512
Gain (loss) on real estate dispositions, net	373,662		287,869
Net other assets/liabilities disposed	5,090		22,470
Proceeds from real estate dispositions	$	1,208,501	$	1,237,851

Dispositions and Assets Held for Sale

Pursuant to our adoption of ASU No. 2014-08, “Presentation of Financial Statements (Topic 205) and Property, Plant and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity”, operating results attributable to properties sold subsequent to or classified as held for sale after January 1, 2014 and which do not meet the definition of discontinued operations are no longer reclassified on our Consolidated Statements of Comprehensive Income. The following represents the activity related to these properties for the periods presented (in thousands):



	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Revenues:
Total revenues	$	29,035	$	52,584	$	92,447	$	175,934
Expenses:
Interest expense	18		1,243		261		5,514
Property operating expenses	21,312		19,147		59,640		58,525
Provision for depreciation	801		10,999		6,605		33,806
Total expenses	22,131		31,389		66,506		97,845
Income (loss) from real estate dispositions, net	$	6,904	$	21,195	$	25,941	$	78,089