The number of the company's communities securing the Long-term debt instrument.

No definition available.

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

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of long-term debt outstanding calculated at point in time.

+ References

No definition available.

+ Details

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

- Definition

The cash outflow for cost incurred in the modification of term of existing debt agreement in order for the entity to achieve some advantage.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

+ Details

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

- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

No definition available.

+ Details

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

- Definition

The cash outflow from a repayment of a borrowing having initial term of repayment of more than three months. Includes repayments of short-term and long-term debt.

+ References

No definition available.

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=bkd_FixedRateInterestFirstMortgageLoanObtainedInDecember2016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
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Debt - 2016 Financings (Details) $ in Millions	1 Months Ended		12 Months Ended
Debt - 2016 Financings (Details) $ in Millions	Dec. 31, 2016 USD ($) community	Mar. 31, 2016 USD ($) community	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Debt Instrument [Line Items]
Payments of debt restructuring			$ 12.4	$ 9.2
First Mortgage loan refinanced in March 2016
Debt Instrument [Line Items]
Proceeds from debt financing		$ 100.0
Number of communities securing mortgage notes \| community		10
Weighted average interest rate		4.20%
Fixed interest rate first mortgage loan obtained in December 2016
Debt Instrument [Line Items]
Proceeds from debt financing	$ 105.0
Weighted average interest rate	4.65%			4.65%
Repayments of debt	$ 164.4
Variable interest rate first mortgage loan obtained in December 2016
Debt Instrument [Line Items]
Proceeds from debt financing	$ 69.6
Number of communities securing mortgage notes \| community	6
LIBOR \| Variable interest rate first mortgage loan obtained in December 2016
Debt Instrument [Line Items]
Basis spread on variable rate basis	2.58%