Note 2 - Mortgage-backed Securities, At Fair Value (Details Textual) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Notional Balance, Interest Only Securities Portfolio, Amount	$ 94,900		$ 98,600
Notional Balance, Inverse Interest Only Securities Portfolio, Amount	25,800		$ 26,800
Collateralized Mortgage-Backed Securities [Member]
Investment Sold at Carrying Value	$ (221,700)	$ (0)

Represents the notional balance for the inverse interest only securities portfolio.

No definition available.

Name:	orc_NotionalBalanceInverseInterestOnlySecuritiesPortfolioAmount
Namespace Prefix:	orc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant