Represents related to the Company number of defendants related to the entity.

No definition available.

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

- Definition

Represents the number of defendants removed due to consolidation of lawsuits.

+ References

No definition available.

+ Details

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

- Definition

Number of defendants named in a legal action who are corporate and partnership entities.

+ References

No definition available.

+ Details

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

- Definition

Number of defendants named in a legal action who are individuals.

+ References

No definition available.

+ Details

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

- Definition

Represents the number of lawsuits consolidated.

+ References

No definition available.

+ Details

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

- Definition

Represents the number of lawsuits after amendment.

+ References

No definition available.

+ Details

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

- Definition

Represents the number of lawsuits before amendment.

+ References

No definition available.

+ Details

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

- Definition

Represents the number of defendants remaining due to consolidation of lawsuits.

+ References

No definition available.

+ Details

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

- Definition

Amount of litigation expense, including but not limited to legal, forensic, accounting, and investigative fees.

+ References

No definition available.

+ Details

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

- Definition

Amount of loss contingency liability expected to be resolved within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349

+ Details

Name:	us-gaap_LossContingencyAccrualCarryingValueCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The total number of new claims filed pertaining to a loss contingency during the period.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of defendants named in a legal action.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

Name:	srt_RangeAxis=srt_MaximumMember
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- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=abr_MotionToAmendmentLawsuitsMember
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Commitments and Contingencies - Litigation (Details) $ in Millions	1 Months Ended
	Dec. 31, 2022 USD ($)	Jun. 30, 2013 lawsuit defendant	Jun. 30, 2011 defendant lawsuit	Mar. 31, 2023 USD ($)
Commitments and Contingencies
Litigation settlement amount \| $				$ 38.0
Lawsuits filed by Extended Stay Litigation Trust (the Trust)
Commitments and Contingencies
Number of lawsuits or complaints filed \| lawsuit			3
Number of defendants			73
Number of defendants who are corporate and partnership entities			55
Number of defendants named in a legal action who are individuals			18
Lawsuits filed by Extended Stay Litigation Trust (the Trust) \| Maximum
Commitments and Contingencies
Litigation settlement, expense \| $	$ 7.4
Lawsuits filed by Extended Stay Litigation Trust (the Trust) \| Motion to amend the lawsuits
Commitments and Contingencies
Number of lawsuits consolidated \| lawsuit		1
Number of defendants who are corporate and partnership entities		16
Number of defendants named in a legal action who are individuals		10
Number of defendants removed due to consolidation of lawsuits		47
Number of defendants related to the entity		0
Number of defendants remaining due to consolidation of lawsuits		26
Number of lawsuits before amendment \| lawsuit		100
Number of lawsuits after amendment \| lawsuit		17