Impairments	12 Months Ended
Impairments	Dec. 31, 2020
Asset Impairment Charges [Abstract]
Impairments	Impairments Real Estate During the year ended December 31, 2020, the Company recognized an aggregate impairment charge of $210 million ($201 million of which is reported in income (loss) from discontinued operations) related to 42 SHOP assets, 5 senior housing triple-net assets, 5 MOBs, and 1 undeveloped MOB land parcel as a result of being classified as held for sale and wrote down their aggregate carrying value of $960 million to their aggregate fair value, less estimated costs to sell, of $750 million. Additionally, during the year ended December 31, 2020, the Company recognized an impairment charge of $15 million related to one life science facility that it intends to demolish for a future development project. 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 an income approach and/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, (iv) negotiations with prospective 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 and as of the year ended December 31, 2020, the Company’s fair value estimates primarily relied on a market approach and utilized prices per unit ranging from $13,000 to $300,000, with a weighted average price per unit of $164,000. When utilizing the income approach, assumptions include, but are not limited to, terminal capitalization rates ranging from 5.5% to 7.5% and discount rates ranging from 8.0% to 9.5%. During the year ended December 31, 2019, the Company recognized an aggregate impairment charge of $194 million ($189 million of which is reported in income (loss) from discontinued operations) related to 8 senior housing triple-net assets, 27 SHOP assets, 3 MOBs, and 1 other non-reportable asset as a result of being classified as held for sale and wrote down their aggregate carrying value of $416 million 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 for a future development project. 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. For the Company’s impairment calculations during and as of 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. 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 were 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 ($9 million of which is reported in income (loss) from discontinued operations). The fair value of the assets are considered to be Level 2 measurements within the fair value hierarchy. During the year ended December 31, 2018, in conjunction with classifying the assets as held for sale, the Company determined that 17 underperforming SHOP assets and one 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 ($44 million of which is reported in income (loss) from discontinued operations), during the year ended December 31, 2018 to write-down the carrying value of the assets to their respective fair values (less estimated 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. 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. Of the total $5 million, $2 million is recorded in other income (expense), net, and $3 million is recorded in income (loss) from discontinued operations. Other See Note 7 for information on the impairment charge related to the write-down of a DFL portfolio to its fair value. See Note 8 for information related to the Company's reserve for loan losses. See Note 9 for information on the impairment charge related to an asset classified as held-for-sale within the CCRC JV.