Loans Held For Investment - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2022	Dec. 31, 2021
Schedule Of Investments [Line Items]
Mortgage loans, at fair value	$ 29,375	$ 29,697
Revolving Credit Facility
Schedule Of Investments [Line Items]
Loan Rate	SOFR plus 3.86
Revolving credit facility, committed fund	$ 30,000	30,000
Revolving credit facility	$ 130,000	$ 130,000
Revolving credit facility maturity date	Jul. 07, 2024
Unused commitment fee percentage	0.50%	0.50%
Revolving credit facility, unfunded commitment	$ 30,000	$ 30,000
Revolving Credit Facility \| Minimum
Schedule Of Investments [Line Items]
Loan floor rate	1.00%	1.00%
Healthcare Facilities Mortgage Loan
Schedule Of Investments [Line Items]
Outstanding principal balance	$ 29,375	$ 29,697
Healthcare Facilities Mortgage Loan \| Loan Purchase Commitments
Schedule Of Investments [Line Items]
Loan Rate	SOFR plus 5.61%
Loan maturity date	Mar. 23, 2022
New loan maturity date	Mar. 23, 2023

Line of credit facility committed fund.

No definition available.

Name:	aaic_LineOfCreditFacilityCommittedFund
Namespace Prefix:	aaic_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of credit facility unfunded commitment.

+ References

No definition available.

+ Details

Name:	aaic_LineOfCreditFacilityUnfundedCommitment
Namespace Prefix:	aaic_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The reference rate for the variable rate of the instrument.

+ References

No definition available.

+ Details

Name:	aaic_MortgageLoanDescriptionOfVariableRateBasis
Namespace Prefix:	aaic_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

New investment maturity date.

+ References

No definition available.

+ Details

Name:	aaic_NewInvestmentMaturityDate
Namespace Prefix:	aaic_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Rate of interest on investment.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27232-111563

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27161-111563

+ Details

Name:	us-gaap_InvestmentInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maturity date of investment, in YYYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27232-111563

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27161-111563

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

+ Details

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

- Definition

Date the credit facility terminates, in YYYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-URI https://asc.fasb.org/subtopic&trid=2196772

+ Details

Name:	us-gaap_LoansReceivableFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
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-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522

+ Details

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

- 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

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

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_InvestmentTypeAxis=aaic_HealthcareFacilitiesMortgageLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_LoanPurchaseCommitmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: