Impairments	12 Months Ended
Dec. 31, 2018
Asset Impairment Charges [Abstract]
Impairments	Impairments Real Estate During 2018, in conjunction with classifying the assets as held for sale, the Company determined that 17 underperforming SHOP assets and an undeveloped life science land parcel were impaired. Additionally, the Company determined that three additional underperforming SHOP assets that were candidates for potential future sale were impaired under the held-for-use impairment model. Accordingly, the Company recognized total impairment charges of $52 million during 2018 to write-down the carrying value of the assets to their respective fair values (less an estimate of costs to sell for assets classified as held for sale). The fair value of the assets was based on contracted or forecasted sales prices and expected future cash flows, which are considered to be Level 2 measurements within the fair value hierarchy. During 2017, the Company determined that 11 underperforming senior housing triple-net assets that were candidates for potential future sale were impaired under the held-for-use impairment model. Accordingly, the Company wrote-down the carrying amount of these 11 assets to their fair value, which resulted in an aggregate impairment charge of $23 million. The fair value of the assets was based on forecasted sales prices which are considered to be Level 2 measurements within the fair value hierarchy. Casualty-Related As a result of Hurricane Harvey and Hurricane Irma during the year ended December 31, 2017, the Company recorded an estimated $13 million of casualty-related losses, net of a small insurance recovery. The losses are comprised of $8 million of property damage and $5 million of other associated costs, including storm preparation, clean up, relocation and other costs. Of the total $13 million casualty losses incurred, $12 million was recorded in other income (expense), net, and $1 million was recorded in equity income (loss) from unconsolidated joint ventures as it relates to casualty losses for properties owned by certain of our unconsolidated joint ventures. In addition, the Company recorded a $1 million deferred tax benefit associated with the casualty-related losses. Other See Note 7 for information on the impairment charge related to the mezzanine loan facility to Tandem and the impairment recovery related to Four Season Notes.

Impairments

Real Estate

During 2018, in conjunction with classifying the assets as held for sale, the Company determined that 17 underperforming SHOP assets and an undeveloped life science land parcel were impaired. Additionally, the Company determined that three additional underperforming SHOP assets that were candidates for potential future sale were impaired under the held-for-use impairment model. Accordingly, the Company recognized total impairment charges of $52 million during 2018 to write-down the carrying value of the assets to their respective fair values (less an estimate of costs to sell for assets classified as held for sale). The fair value of the assets was based on contracted or forecasted sales prices and expected future cash flows, which are considered to be Level 2 measurements within the fair value hierarchy.

During 2017, the Company determined that 11 underperforming senior housing triple-net assets that were candidates for potential future sale were impaired under the held-for-use impairment model. Accordingly, the Company wrote-down the carrying amount of these 11 assets to their fair value, which resulted in an aggregate impairment charge of $23 million. The fair value of the assets was based on forecasted sales prices which are considered to be Level 2 measurements within the fair value hierarchy.

Casualty-Related

As a result of Hurricane Harvey and Hurricane Irma during the year ended December 31, 2017, the Company recorded an estimated $13 million of casualty-related losses, net of a small insurance recovery. The losses are comprised of $8 million of property damage and $5 million of other associated costs, including storm preparation, clean up, relocation and other costs. Of the total $13 million casualty losses incurred, $12 million was recorded in other income (expense), net, and $1 million was recorded in equity income (loss) from unconsolidated joint ventures as it relates to casualty losses for properties owned by certain of our unconsolidated joint ventures. In addition, the Company recorded a $1 million deferred tax benefit associated with the casualty-related losses.

Other

See Note 7 for information on the impairment charge related to the mezzanine loan facility to Tandem and the impairment recovery related to Four Season Notes.