Note 3 - U.S. Treasury Securities, Available-for-sale - Available-for-sale Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
U.S. Treasury securities, available for sale, amortized cost	$ 154,956	$ 134,715
Pledged assets, available for sale	155,095	135,133
U.S. Treasury Note, 4.625%, 6/30/2026 Maturity [Member]
U.S. Treasury securities, available for sale, amortized cost	100,068	100,136
Gross unrealized gains	162	395
Gross unrealized losses	0	0
Pledged assets, available for sale	100,230	100,531
U.S. Treasury Note, 0.75%, 5/31/2026 Maturity [Member]
U.S. Treasury securities, available for sale, amortized cost	34,832	34,579
Gross unrealized gains	0	23
Gross unrealized losses	(4)
Pledged assets, available for sale	34,828	34,602
U.S. Treasury Note, 4.125%, 10/31/2026 Maturity [Member]
U.S. Treasury securities, available for sale, amortized cost	20,056
Gross unrealized gains	0
Gross unrealized losses	(19)
Pledged assets, available for sale	20,037
US Treasury Securities [Member]
U.S. Treasury securities, available for sale, amortized cost	154,956	134,715
Gross unrealized gains	162	418
Gross unrealized losses	(23)	0
Pledged assets, available for sale	$ 155,095	$ 135,133

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

+ Details

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

- Definition

Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

+ Details

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

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479130/326-30-45-1

+ Details

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

- Definition

Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477657/942-210-S45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478478/942-210-S50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479130/326-30-45-1

+ Details

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

- Details

Name:	us-gaap_FinancialInstrumentAxis=orc_UsTreasuryNote46256302026MaturityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=orc_UsTreasuryNote0755312026MaturityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=orc_UsTreasuryNote412510312026MaturityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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