Impairments	12 Months Ended
Impairments	Dec. 31, 2019
Asset Impairment Charges [Abstract]
Impairments	Impairments Real Estate During the year ended December 31, 2019, the Company recognized an aggregate impairment charge of $194 million in conjunction with classifying 8 senior housing triple-net assets, 27 SHOP assets, 3 MOBs, and 1 other non-reportable asset as held for sale and writing their aggregate carrying value of $416 million down to their aggregate fair value less estimated costs to sell of $223 million. During the year ended December 31, 2019, the Company also recognized an impairment charge of $4 million related to one MOB that it intends to demolish. Additionally, during the year ended December 31, 2019, the Company determined the carrying value of two MOBs and one SHOP asset that were candidates for potential future sale was no longer recoverable due to the Company’s shortened intended hold period under the held-for-use impairment model. Accordingly, the Company wrote-down the carrying amount of these three assets to their respective fair value, which resulted in an aggregate impairment charge of $18 million. The fair value of the impaired assets was based on forecasted sales prices, which are considered to be Level 3 measurements within the fair value hierarchy. Forecasted sales prices were determined using a direct capitalization model or a market approach (comparable sales model), which rely on certain assumptions by management, including: (i) market capitalization rates, (ii) comparable market transactions, (iii) estimated prices per unit or per square foot, (iv) negotiations with perspective buyers, and (v) forecasted cash flow streams (lease revenue rates, expense rates, growth rates, etc.). There are inherent uncertainties in making these assumptions. For the Company’s impairment calculations during the year ended December 31, 2019, the Company estimated the fair value of each asset using either (i) market capitalization rates ranging from 4.97% to 8.27%, with a weighted average rate of 6.22%, or (ii) prices per unit ranging from $24,000 to $125,000, with a weighted average price of $73,000. 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 the carrying value of 11 underperforming senior housing triple-net assets that were candidates for potential future sale was no longer recoverable due to the Company's shortened intended hold period under the held-for-use impairment model. Accordingly, the Company wrote-down the carrying amount of these 11 assets to their respective fair values, 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 During the year ended December 31, 2019, the Company recognized a $5 million casualty-related gain, net of deferred tax impacts, as a result of insurance proceeds received for property damage and other associated costs related to hurricanes in 2017. The gain is recorded in other income (expense), net. 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 certain affiliates of Tandem Health Care (together with its affiliates, "Tandem) and the impairment recovery related to Four Seasons Notes (as defined below). See Note 8 for information on the impairment charge related to an asset classified as held-for-sale within the CCRC JV. See Note 6 for information on the impairment charge related to the write-down of a DFL portfolio to its fair value.