Line Of Credit Facility, Accordion Feature, Increase Limit

No definition available.

Name:	arcc_LineOfCreditFacilityAccordionFeatureIncreaseLimit
Namespace Prefix:	arcc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(a)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-2

+ Details

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

- Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_BaseRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=arcc_July2025NotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_SecuredOvernightFinancingRateSofrMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

SUBSEQUENT EVENTS (Details) - USD ($) $ in Millions				6 Months Ended	7 Months Ended	8 Months Ended	11 Months Ended	27 Months Ended	30 Months Ended
SUBSEQUENT EVENTS (Details) - USD ($) $ in Millions	Jul. 29, 2025	Jul. 28, 2025	Oct. 08, 2024	Jun. 30, 2025	Jun. 30, 2025	Dec. 05, 2024	Mar. 27, 2024	Oct. 08, 2024	Sep. 30, 2024	Jul. 31, 2025	Jul. 30, 2025	Dec. 31, 2024
Revolving Credit Facility
Subsequent Event [Line Items]
Line of credit, borrowing capacity incremental increase limit				$ 7,925	$ 7,925							$ 6,732
Revolving Credit Facility \| Line of Credit
Subsequent Event [Line Items]
Total Aggregate Principal Amount Committed/ Outstanding				$ 5,393	$ 5,393
Interest rate spread				1.65%					0.10%
Revolving Credit Facility \| Line of Credit \| Base Rate
Subsequent Event [Line Items]
Interest rate spread				1.525%
July 2025 Notes \| Senior Notes
Subsequent Event [Line Items]
Effective stated interest rate				3.25%	3.25%
SMBC Funding Facility
Subsequent Event [Line Items]
Line of credit, borrowing capacity incremental increase limit				$ 1,000	$ 1,000
SMBC Funding Facility \| Line of Credit
Subsequent Event [Line Items]
Total Aggregate Principal Amount Committed/ Outstanding				800	$ 800
Interest rate spread					2.00%	2.50%	0.10%
SMBC Funding Facility \| Line of Credit \| Base Rate
Subsequent Event [Line Items]
Interest rate spread					1.00%	1.50%
Revolving Funding Facility \| Line of Credit
Subsequent Event [Line Items]
Total Aggregate Principal Amount Committed/ Outstanding				$ 2,150	$ 2,150
Interest rate spread			2.00%					1.90%
Revolving Funding Facility \| Line of Credit \| Secured Overnight Financing Rate (SOFR)
Subsequent Event [Line Items]
Interest rate spread								0.10%
Subsequent Event \| Revolving Credit Facility \| Line of Credit
Subsequent Event [Line Items]
Total Aggregate Principal Amount Committed/ Outstanding										$ 5,493	$ 5,393
Subsequent Event \| July 2025 Notes \| Senior Notes
Subsequent Event [Line Items]
Effective stated interest rate	3.25%
Subsequent Event \| SMBC Funding Facility \| Line of Credit
Subsequent Event [Line Items]
Total Aggregate Principal Amount Committed/ Outstanding	$ 1,100	$ 800
Line of credit, borrowing capacity incremental increase limit	$ 1,300
Subsequent Event \| SMBC Funding Facility \| Line of Credit \| Base Rate
Subsequent Event [Line Items]
Interest rate spread	0.80%	1.00%
Subsequent Event \| SMBC Funding Facility \| Line of Credit \| Secured Overnight Financing Rate (SOFR)
Subsequent Event [Line Items]
Interest rate spread	1.80%	2.00%
Subsequent Event \| Revolving Funding Facility \| Line of Credit
Subsequent Event [Line Items]
Total Aggregate Principal Amount Committed/ Outstanding	$ 2,250	$ 2,150
Interest rate spread	1.80%	2.00%