Maximum percentage payroll deduction per employee per quarter.

No definition available.

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- Definition

Percentage of closing market price paid for purchase of common stock shares through employee stock purchase plan.

+ References

No definition available.

+ Details

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Namespace Prefix:	bkd_
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Balance Type:	na
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- Definition

The floor of a customized range of grant date fair values for purposes of disclosing shares potentially issuable under restricted stock awards on all restricted stock plans and other required information pertaining to awards in the customized range.

+ References

No definition available.

+ Details

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- Definition

The ceiling of a customized range of grant date fair values for purposes of disclosing shares potentially issuable under restricted stock awards on all restricted stock plans and other required information pertaining to awards in the customized range.

+ References

No definition available.

+ Details

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- Definition

Number of committed-to-be-released shares held by the Employee Stock Purchase Plan. Committed-to-be-released shares are shares that will be released in the future.

+ References

No definition available.

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
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- Definition

Number of reserved shares held by the Employee Stock Purchase Plan.

+ References

No definition available.

+ Details

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Namespace Prefix:	bkd_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The maximum percentage rate stock-based compensation expense is calculated using net of forfeitures estimated from shares granted.

+ References

No definition available.

+ Details

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

- Definition

The estimated measure of the percentage of shares, units or grants expected to be forfeited.

+ References

No definition available.

+ Details

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Namespace Prefix:	bkd_
Data Type:	num:percentItemType
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- Definition

Grant date fair value of stock related to Restricted Stock Awards granted during the period.

+ References

No definition available.

+ Details

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

- Definition

As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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Period Type:	duration

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

+ Details

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Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

+ Details

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(c)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(b)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(a)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(b)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(a)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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Data Type:	num:perShareItemType
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Period Type:	instant

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

+ Details

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Period Type:	duration

- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References

+ Details

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Stock-Based Compensation (Details) (USD $)	12 Months Ended				3 Months Ended				12 Months Ended
Stock-Based Compensation (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012 Restricted Stock [Member]	Sep. 30, 2012 Restricted Stock [Member]	Jun. 30, 2012 Restricted Stock [Member]	Mar. 31, 2012 Restricted Stock [Member]	Dec. 31, 2012 Employee Stock Purchase Plan [Member]
Restricted stock awards [Roll Forward]
Balance (in shares)	3,952,000	4,222,000	3,540,000	3,915,000
Granted (in shares)	1,592,000	2,091,000	1,341,000		93,000	128,000	85,000	1,286,000
Vested (in shares)	(1,435,000)	(1,207,000)	(1,423,000)
Cancelled or forfeited (in shares)	(427,000)	(202,000)	(293,000)
Weighted-average grant-date fair value of restricted shares and restricted stock units granted (in dollars per share)	$ 19.20	$ 16.20	$ 16.92
Weighted-average grant-date fair value of restricted shares and restricted stock units vested (in dollars per share)	$ 14.28	$ 16.43	$ 16.90
Weighted-average grant-date fair value of restricted shares and restricted stock units cancelled/forfeited (in dollars per share)	$ 15.62	$ 15.34	$ 15.93
Weighted-average grant-date fair value of restricted shares and restricted stock units unvested (in dollars per share)	$ 16.67	$ 14.93	$ 14.76	$ 14.62
Unrecognized compensation cost related to nonvested share-based compensation arrangements granted	$ 44,200,000
Period over which cost is expected to be recognized (in years)	2 years 5 months
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Shares Granted (in shares)	1,592,000	2,091,000	1,341,000		93,000	128,000	85,000	1,286,000
Value Per Share minimum (in dollars per share)					$ 23.31	$ 16.66	$ 18.72	$ 17.39
Value Per Share maximum (in dollars per share)					$ 23.99	$ 17.74	$ 19.55	$ 19.07
Total value of restricted shares granted					$ 2,231,000	$ 2,135,000	$ 1,666,000	$ 24,524,000
Percentage of estimated forfeitures, minimum	0.00%
Percentage of estimated forfeitures, maximum	10.00%
Percentage payroll deduction that each employee may deduct									15.00%
Percentage of closing market price paid for purchase of whole shares									90.00%
Initial number of shares reserved (in shares)									1,000,000
Annual increase in number of shares available for issuance (in shares)									200,000