Disposal Group, Number Of Communities Disposed Of

No definition available.

Name:	bkd_DisposalGroupNumberOfCommunitiesDisposedOf
Namespace Prefix:	bkd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Master Leases Not Renewed, Number Of Communities

+ References

No definition available.

+ Details

Name:	bkd_MasterLeasesNotRenewedNumberOfCommunities
Namespace Prefix:	bkd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number Of Communities Managed

+ References

No definition available.

+ Details

Name:	bkd_NumberOfCommunitiesManaged
Namespace Prefix:	bkd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Lease Portfolios

+ References

No definition available.

+ Details

Name:	bkd_NumberOfLeasePortfolios
Namespace Prefix:	bkd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Leases Not Renewed

+ References

No definition available.

+ Details

Name:	bkd_NumberOfLeasesNotRenewed
Namespace Prefix:	bkd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Operating Leases, Number Of Communities

+ References

No definition available.

+ Details

Name:	bkd_OperatingLeasesNumberOfCommunities
Namespace Prefix:	bkd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Payments (Proceeds) For Lease Termination

+ References

No definition available.

+ Details

Name:	bkd_PaymentsProceedsForLeaseTermination
Namespace Prefix:	bkd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Potential Lease Terminations, Rent Credit Percentage

+ References

No definition available.

+ Details

Name:	bkd_PotentialLeaseTerminationsRentCreditPercentage
Namespace Prefix:	bkd_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The difference between the carrying value and the sale price of equity securities, not separately or otherwise categorized as trading or available-for-sale. This element includes investments in which the entity holds a small ownership stake (generally, less than 20% of the shares outstanding) and cannot exert significant influence.

+ References

No definition available.

+ Details

Name:	us-gaap_GainLossOnSaleOfEquityInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of gain (loss) on termination of lease before expiration of lease term.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 40
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=77888415&loc=SL77918607-209975

+ Details

Name:	us-gaap_GainLossOnTerminationOfLease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

No definition available.

+ Details

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow associated with the sale of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromSaleOfEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	bkd_ByTransactionNameAxis=bkd_WelltowerLeaseTransactionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=bkd_A37CommunitiesDisposedOfThroughLeaseTerminationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=bkd_WelltowerInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bkd_ByTransactionNameAxis=bkd_WelltowerLeaseTransactionsLeasePortfolioMaturingIn2028Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	bkd_ByTransactionNameAxis=bkd_WelltowerLeaseTransactionsLeasePortfolioMaturingIn2020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=bkd_WelltowerRIDEAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Acquisitions, Dispositions and Other Significant Transactions - Welltower Lease and RIDEA Venture Restructuring (Details) $ in Thousands		3 Months Ended				12 Months Ended
	Jun. 30, 2018 USD ($) lease_portfolio community	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($) lease community	Jun. 30, 2018 USD ($) community	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($) community	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments for lease termination						$ 12,548	$ 552	$ 9,250
Loss on facility lease termination and modification, net		$ 13,197	$ 2,337	$ 146,467	$ 0	162,001	14,276	11,113
Base rent						$ 303,294	$ 339,721	$ 373,635
Welltower Lease Transactions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number Of Leases Not Renewed \| lease			2
Master Leases Not Renewed, Number Of Communities \| community			11
Number of communities managed \| community						74
Welltower Lease Transactions \| 37 Communities Disposed Of Through Lease Terminations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of communities disposed of \| community	37
Loss on facility lease termination and modification, net						$ 22,600
Welltower Inc. \| Welltower Lease Transactions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of lease portfolios \| lease_portfolio	2
Payments for lease termination	$ 58,000
Rent credit, potential future lease terminations	6.25%
Welltower Inc. \| Welltower Lease Transactions, Lease Portfolio Maturing In 2028
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of communities leased \| community	27			27
Welltower Inc. \| Welltower Lease Transactions, Lease Portfolio Maturing In 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of communities leased \| community	10			10
Maximum \| Welltower Inc. \| Welltower Lease Transactions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Base rent	$ 5,000
Welltower RIDEA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership Percentage	20.00%			20.00%
Welltower RIDEA \| Welltower Inc.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of equity method investment	$ 33,500
Gain on sale of equity method investment	$ 14,700