Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States ("GAAP") and pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC") for quarterly reports on Form 10-Q. In the opinion of management, these financial statements include all adjustments, which are of a normal and recurring nature, necessary to present fairly the financial position, results of operations, and cash flows of the Company for all periods presented. Certain information and footnote disclosures included in annual financial statements have been condensed or omitted. The Company believes that the disclosures included are adequate and provide a fair presentation of interim period results. Interim financial statements are not necessarily indicative of the financial position or operating results for an entire year. These interim financial statements should be read in conjunction with the audited financial statements and the notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2019 filed with the SEC on February 19, 2020. Certain prior period amounts have been reclassified to conform to the current financial statement presentation, with no effect on the Company's condensed consolidated financial position or results of operations. Except for the changes for the impact of the recently adopted accounting pronouncements discussed in this Note, the Company has consistently applied its accounting policies to all periods presented in these condensed consolidated financial statements.
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of Brookdale and its consolidated subsidiaries. All intercompany balances and transactions have been eliminated upon consolidation. Investments in affiliated companies that the Company does not control, but has the ability to exercise significant influence over governance and operations, are accounted for by the equity method. The ownership interest of consolidated entities not wholly-owned by the Company are presented as noncontrolling interests in the accompanying condensed consolidated financial statements. Noncontrolling interest represents the share of consolidated entities owned by third parties. Noncontrolling interest is adjusted for the noncontrolling holder's share of additional contributions, distributions, and the proportionate share of the net income or loss of each respective entity.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements and related disclosures in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Estimates are used for, but not limited to, revenue, asset impairments, self-insurance reserves, performance-based compensation, the allowance for credit losses, depreciation and amortization, leasing transactions, income taxes, and other contingencies. Although these estimates are based on management's best knowledge of current events and actions that the Company may undertake in the future, actual results may differ from the original estimates.
Lease Accounting	Lease Accounting The Company, as lessee, recognizes a right-of-use asset and a lease liability on the Company's consolidated balance sheet for its community, office, and equipment leases. As of the commencement date of a lease, a lease liability and corresponding right-of-use asset is established on the Company's consolidated balance sheet at the present value of future minimum lease payments. The Company's community leases generally contain fixed annual rent escalators or annual rent escalators based on an index, such as the consumer price index. The future minimum lease payments recognized on the consolidated balance sheet include fixed payments (including in-substance fixed payments) and variable payments estimated utilizing the index or rate on the lease commencement date. The Company recognizes lease expense as incurred for additional variable payments. For the Company's leases that do not contain an implicit rate, the Company utilizes its estimated incremental borrowing rate to determine the present value of lease payments based on information available at commencement of the lease. The Company's estimated incremental borrowing rate reflects the fixed rate at which the Company could borrow a similar amount for the same term on a collateralized basis. The Company elected the short-term lease exception policy which permits leases with an initial term of 12 months or less to not be recorded on the Company's consolidated balance sheet and instead to be recognized as lease expense as incurred. The Company, as lessee, makes a determination with respect to each of its community, office, and equipment leases as to whether each should be accounted for as an operating lease or financing lease. The classification criteria is based on estimates regarding the fair value of the leased asset, minimum lease payments, effective cost of funds, economic life of the asset, and certain other terms in the lease agreements. Lease right-of-use assets are reviewed for impairment whenever changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of right-of-use assets are assessed by a comparison of the carrying amount of the asset to the estimated future undiscounted net cash flows expected to be generated by the asset, calculated utilizing the lowest level of identifiable cash flows. If estimated future undiscounted net cash flows are less than the carrying amount of the asset then the fair value of the asset is estimated. The impairment expense is determined by comparing the estimated fair value of the asset to its carrying amount, with any amount in excess of fair value recognized as an expense in the current period. Undiscounted cash flow projections and estimates of fair value amounts are based on a number of assumptions such as revenue and expense growth rates and estimated lease coverage ratios (Level 3). Operating Leases The Company recognizes operating lease expense for actual rent paid, generally plus or minus a straight-line adjustment for estimated minimum lease escalators if applicable. The right-of-use asset is generally reduced each period by an amount equal to the difference between the operating lease expense and the amount of expense on the lease liability utilizing the effective interest method. Subsequent to the impairment of an operating lease right-of-use asset, the Company recognizes operating lease expense consisting of the reduction of the right-of-use asset on a straight-line basis over the remaining lease term and the amount of expense on the lease liability utilizing the effective interest method. Financing Leases Financing lease right-of-use assets are recognized within property, plant and equipment and leasehold intangibles, net on the Company's consolidated balance sheets. The Company recognizes interest expense on the financing lease liabilities utilizing the effective interest method. The right-of-use asset is generally amortized to depreciation and amortization expense on a straight-line basis over the lease term unless the lease contains an option to purchase the underlying asset that the Company is reasonably certain to exercise. If the Company is reasonably certain to exercise the purchase option, the asset is amortized over the useful life. Sale-Leaseback Transactions For transactions in which an owned community is sold and leased back from the buyer (sale-leaseback transactions), the Company recognizes an asset sale and lease accounting is applied if the Company has transferred control of the community. For such transactions, the Company removes the transferred assets from the consolidated balance sheet and a gain or loss on the sale is recognized for the difference between the carrying amount of the asset and the transaction price for the sale transaction. For sale‑leaseback transactions in which the Company has not transferred control of the underlying asset, the Company does not recognize an asset sale or derecognize the underlying asset until control is transferred. For such transactions, the Company continues to recognize the assets within property, plant and equipment and leasehold intangibles, net and continues to depreciate the asset over its useful life. Additionally, the Company accounts for any amounts received as a financing lease liability and the Company recognizes interest expense on the financing lease liability utilizing the effective interest method with the interest expense limited to an amount that is not greater than the cash payments on the financing lease liability over the term of the lease.
Gain (Loss) on Sale of Assets	Gain (Loss) on Sale of Assets The Company regularly enters into real estate transactions which may include the disposal of certain communities, including the associated real estate. The Company recognizes gain or loss from real estate sales when the transfer of control is complete. The Company recognizes gain or loss from the sale of equity method investments when the transfer of control is complete and the Company has no continuing involvement with the transferred financial assets.
Property, Plant and Equipment and Leasehold Intangibles, Net	Property, Plant and Equipment and Leasehold Intangibles, Net Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset group may not be recoverable. Recoverability of an asset group is assessed by comparing its carrying amount to the estimated future undiscounted net cash flows expected to be generated by the asset group through operation or disposition, calculated utilizing the lowest level of identifiable cash flows. If this comparison indicates that the carrying amount of an asset group is not recoverable, the Company is required to recognize an impairment loss. The impairment loss is measured by the amount by which the carrying amount of the asset exceeds its estimated fair value, with any amount in excess of fair value recognized as an expense in the current period. Undiscounted cash flow projections and estimates of fair value amounts are based on a number of assumptions such as revenue and expense growth rates, estimated holding periods, and estimated capitalization rates (Level 3).
Goodwill	Goodwill The Company tests goodwill for impairment annually during the fourth quarter or more frequently if indicators of impairment arise. Factors the Company considers important in its analysis of whether an indicator of impairment exists include a significant decline in the Company's stock price or market capitalization for a sustained period since the last testing date, significant underperformance relative to historical or projected future operating results, and significant negative industry or economic trends. The Company first assesses qualitative factors to determine if it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If so, the Company performs a quantitative goodwill impairment test based upon a comparison of the estimated fair value of the reporting unit to which the goodwill has been assigned with the reporting unit's carrying amount. The fair values used in the quantitative goodwill impairment test are estimated using Level 3 inputs based upon discounted future cash flow projections for the reporting unit. These cash flow projections are based upon a number of estimates and assumptions such as revenue and expense growth rates, capitalization rates, and discount rates. The Company also considers market-based measures such as earnings multiples in its analysis of estimated fair values of its reporting units. If the quantitative goodwill impairment test results in a reporting unit's carrying amount exceeding its estimated fair value, an impairment charge will be recorded based on the difference, with the impairment charge limited to the amount of goodwill allocated to the reporting unit.
Recently Adopted Accounting Pronouncements/Recently Issued Accounting Pronouncements Not Yet Adopted	Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"). ASU 2016-13 replaces the current incurred loss impairment methodology for credit losses with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The Company adopted this standard effective January 1, 2020 and recognized the cumulative effect of the adoption as an immaterial adjustment to beginning accumulated deficit as of January 1, 2020 for the cumulative effect of adopting ASU 2016-13. In February 2016, the FASB issued ASU 2016-02, Leases ("ASU 2016-02"), which amends the former accounting principles for the recognition, measurement, presentation, and disclosure of leases for both lessees and lessors. The Company adopted these lease accounting standards effective January 1, 2019 and recognized the cumulative effect of the adoption as a $55.9 million adjustment to beginning accumulated deficit as of January 1, 2019. See Footnote 2, Summary of Significant Accounting Policies, in our Annual Report on Form 10-K for the year ended December 31, 2019 for more details regarding the adoption of this accounting pronouncement.

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2020

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States ("GAAP") and pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC") for quarterly reports on Form 10-Q. In the opinion of management, these financial statements include all adjustments, which are of a normal and recurring nature, necessary to present fairly the financial position, results of operations, and cash flows of the Company for all periods presented. Certain information and footnote disclosures included in annual financial statements have been condensed or omitted. The Company believes that the disclosures included are adequate and provide a fair presentation of interim period results. Interim financial statements are not necessarily indicative of the financial position or operating results for an entire year. These interim financial statements should be read in conjunction with the audited financial statements and the notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2019 filed with the SEC on February 19, 2020. Certain prior period amounts have been reclassified to conform to the current financial statement presentation, with no effect on the Company's condensed consolidated financial position or results of operations.

Except for the changes for the impact of the recently adopted accounting pronouncements discussed in this Note, the Company has consistently applied its accounting policies to all periods presented in these condensed consolidated financial statements.

Principles of Consolidation

The condensed consolidated financial statements include the accounts of Brookdale and its consolidated subsidiaries. All intercompany balances and transactions have been eliminated upon consolidation. Investments in affiliated companies that the Company does not control, but has the ability to exercise significant influence over governance and operations, are accounted for by the equity method. The ownership interest of consolidated entities not wholly-owned by the Company are presented as noncontrolling interests in the accompanying condensed consolidated financial statements. Noncontrolling interest represents the share of consolidated entities owned by third parties. Noncontrolling interest is adjusted for the noncontrolling holder's share of additional contributions, distributions, and the proportionate share of the net income or loss of each respective entity.

Use of Estimates

The preparation of the consolidated financial statements and related disclosures in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Estimates are used for, but not limited to, revenue, asset impairments, self-insurance reserves, performance-based compensation, the allowance for credit losses, depreciation and amortization, leasing transactions, income taxes, and other contingencies. Although these estimates are based on management's best knowledge of current events and actions that the Company may undertake in the future, actual results may differ from the original estimates.

Lease Accounting

The Company, as lessee, recognizes a right-of-use asset and a lease liability on the Company's consolidated balance sheet for its community, office, and equipment leases. As of the commencement date of a lease, a lease liability and corresponding right-of-use asset is established on the Company's consolidated balance sheet at the present value of future minimum lease payments. The Company's community leases generally contain fixed annual rent escalators or annual rent escalators based on an index, such as the consumer price index. The future minimum lease payments recognized on the consolidated balance sheet include fixed payments (including in-substance fixed payments) and variable payments estimated utilizing the index or rate on the lease commencement

date. The Company recognizes lease expense as incurred for additional variable payments. For the Company's leases that do not contain an implicit rate, the Company utilizes its estimated incremental borrowing rate to determine the present value of lease payments based on information available at commencement of the lease. The Company's estimated incremental borrowing rate reflects the fixed rate at which the Company could borrow a similar amount for the same term on a collateralized basis. The Company elected the short-term lease exception policy which permits leases with an initial term of 12 months or less to not be recorded on the Company's consolidated balance sheet and instead to be recognized as lease expense as incurred.

The Company, as lessee, makes a determination with respect to each of its community, office, and equipment leases as to whether each should be accounted for as an operating lease or financing lease. The classification criteria is based on estimates regarding the fair value of the leased asset, minimum lease payments, effective cost of funds, economic life of the asset, and certain other terms in the lease agreements.

Lease right-of-use assets are reviewed for impairment whenever changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of right-of-use assets are assessed by a comparison of the carrying amount of the asset to the estimated future undiscounted net cash flows expected to be generated by the asset, calculated utilizing the lowest level of identifiable cash flows. If estimated future undiscounted net cash flows are less than the carrying amount of the asset then the fair value of the asset is estimated. The impairment expense is determined by comparing the estimated fair value of the asset to its carrying amount, with any amount in excess of fair value recognized as an expense in the current period. Undiscounted cash flow projections and estimates of fair value amounts are based on a number of assumptions such as revenue and expense growth rates and estimated lease coverage ratios (Level 3).

Operating Leases

The Company recognizes operating lease expense for actual rent paid, generally plus or minus a straight-line adjustment for estimated minimum lease escalators if applicable. The right-of-use asset is generally reduced each period by an amount equal to the difference between the operating lease expense and the amount of expense on the lease liability utilizing the effective interest method. Subsequent to the impairment of an operating lease right-of-use asset, the Company recognizes operating lease expense consisting of the reduction of the right-of-use asset on a straight-line basis over the remaining lease term and the amount of expense on the lease liability utilizing the effective interest method.

Financing Leases

Financing lease right-of-use assets are recognized within property, plant and equipment and leasehold intangibles, net on the Company's consolidated balance sheets. The Company recognizes interest expense on the financing lease liabilities utilizing the effective interest method. The right-of-use asset is generally amortized to depreciation and amortization expense on a straight-line basis over the lease term unless the lease contains an option to purchase the underlying asset that the Company is reasonably certain to exercise. If the Company is reasonably certain to exercise the purchase option, the asset is amortized over the useful life.

Sale-Leaseback Transactions

For transactions in which an owned community is sold and leased back from the buyer (sale-leaseback transactions), the Company recognizes an asset sale and lease accounting is applied if the Company has transferred control of the community. For such transactions, the Company removes the transferred assets from the consolidated balance sheet and a gain or loss on the sale is recognized for the difference between the carrying amount of the asset and the transaction price for the sale transaction.

For sale‑leaseback transactions in which the Company has not transferred control of the underlying asset, the Company does not recognize an asset sale or derecognize the underlying asset until control is transferred. For such transactions, the Company continues to recognize the assets within property, plant and equipment and leasehold intangibles, net and continues to depreciate the asset over its useful life. Additionally, the Company accounts for any amounts received as a financing lease liability and the Company recognizes interest expense on the financing lease liability utilizing the effective interest method with the interest expense limited to an amount that is not greater than the cash payments on the financing lease liability over the term of the lease.

Gain (Loss) on Sale of Assets

The Company regularly enters into real estate transactions which may include the disposal of certain communities, including the associated real estate. The Company recognizes gain or loss from real estate sales when the transfer of control is complete.

The Company recognizes gain or loss from the sale of equity method investments when the transfer of control is complete and the Company has no continuing involvement with the transferred financial assets.

Property, Plant and Equipment and Leasehold Intangibles, Net

Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset group may not be recoverable. Recoverability of an asset group is assessed by comparing its carrying amount to the estimated future undiscounted net cash flows expected to be generated by the asset group through operation or disposition, calculated utilizing the lowest level of identifiable cash flows. If this comparison indicates that the carrying amount of an asset group is not recoverable, the Company is required to recognize an impairment loss. The impairment loss is measured by the amount by which the carrying amount of the asset exceeds its estimated fair value, with any amount in excess of fair value recognized as an expense in the current period. Undiscounted cash flow projections and estimates of fair value amounts are based on a number of assumptions such as revenue and expense growth rates, estimated holding periods, and estimated capitalization rates (Level 3).

Goodwill

The Company tests goodwill for impairment annually during the fourth quarter or more frequently if indicators of impairment arise. Factors the Company considers important in its analysis of whether an indicator of impairment exists include a significant decline in the Company's stock price or market capitalization for a sustained period since the last testing date, significant underperformance relative to historical or projected future operating results, and significant negative industry or economic trends. The Company first assesses qualitative factors to determine if it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If so, the Company performs a quantitative goodwill impairment test based upon a comparison of the estimated fair value of the reporting unit to which the goodwill has been assigned with the reporting unit's carrying amount. The fair values used in the quantitative goodwill impairment test are estimated using Level 3 inputs based upon discounted future cash flow projections for the reporting unit. These cash flow projections are based upon a number of estimates and assumptions such as revenue and expense growth rates, capitalization rates, and discount rates. The Company also considers market-based measures such as earnings multiples in its analysis of estimated fair values of its reporting units. If the quantitative goodwill impairment test results in a reporting unit's carrying amount exceeding its estimated fair value, an impairment charge will be recorded based on the difference, with the impairment charge limited to the amount of goodwill allocated to the reporting unit.

Recently Adopted Accounting Pronouncements/Recently Issued Accounting Pronouncements Not Yet Adopted

Recently Adopted Accounting Pronouncements

In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"). ASU 2016-13 replaces the current incurred loss impairment methodology for credit losses with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The Company adopted this standard effective January 1, 2020 and recognized the cumulative effect of the adoption as an immaterial adjustment to beginning accumulated deficit as of January 1, 2020 for the cumulative effect of adopting ASU 2016-13.

In February 2016, the FASB issued ASU 2016-02, Leases ("ASU 2016-02"), which amends the former accounting principles for the recognition, measurement, presentation, and disclosure of leases for both lessees and lessors. The Company adopted these lease accounting standards effective January 1, 2019 and recognized the cumulative effect of the adoption as a $55.9 million adjustment to beginning accumulated deficit as of January 1, 2019. See Footnote 2, Summary of Significant Accounting Policies, in our Annual Report on Form 10-K for the year ended December 31, 2019 for more details regarding the adoption of this accounting pronouncement.