XML 61 R48.htm IDEA: XBRL DOCUMENT v3.23.3

Investments - Schedule of Unrealized Loss on Investments (Details) $ in Thousands	Sep. 30, 2023 USD ($) security	Dec. 31, 2022 USD ($) security
U.S. Government and Agency Securities
Twelve Months or More
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | security	0	3
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0	$ 105
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 0	$ 2,385
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	3	0
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 95	$ 0
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 2,399	$ 0
States, Municipalities and Political Subdivisions
Twelve Months or More
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | security	5	21
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 113	$ 540
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 2,433	$ 7,306
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	44	31
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 3,232	$ 3,525
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 19,837	$ 18,853
Public Utilities
Twelve Months or More
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | security	0	8
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0	$ 193
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 0	$ 2,286
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	12	4
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 692	$ 1,049
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 4,967	$ 5,408
Corporate Securities
Twelve Months or More
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | security	6	78
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 143	$ 2,279
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 2,290	$ 24,594
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	137	77
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 11,307	$ 13,460
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 57,858	$ 57,765
Mortgage-backed securities
Twelve Months or More
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | security	4	48
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 77	$ 1,282
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 908	$ 15,259
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	119	80
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 9,321	$ 7,854
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 45,220	$ 40,856
Asset-backed Securities
Twelve Months or More
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | security	5	16
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 38	$ 795
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 2,135	$ 6,397
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	43	46
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 1,929	$ 1,993
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 14,053	$ 19,028
Fixed Maturities
Twelve Months or More
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | security	20	175
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 371	$ 5,203
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 7,766	$ 59,218
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	359	238
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 26,576	$ 27,881
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 145,334	$ 141,910
Foreign Government
Twelve Months or More
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | security	0	1
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0	$ 9
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 0	$ 991
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	1	0
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 0	$ 0
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 1,000	$ 0

X

- Definition

Available For Sale Securities Continuous Unrealized Loss Position Twelve Months or More [Abstract]

+ References

No definition available.

+ Details

Name:	acic_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsorMoreAbstract
Namespace Prefix:	acic_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479081/326-30-55-8

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-7

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479106/326-30-50-5

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479106/326-30-50-5

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without an allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479106/326-30-50-4

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479081/326-30-55-8

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-7

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479106/326-30-50-5

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479106/326-30-50-5

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-6

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479106/326-30-50-4

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

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