Mortgage-Backed Securities - By Maturity (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Mortgage Backed Securities By Maturity [Abstract]
Greater than five years and less than ten years	$ 12,980,000	$ 2,014,000
Greater than or equal to ten years	102,400,000	53,988,000
Total mortgage-backed securities	$ 115,379,574	$ 56,001,584

Investments in mortgage backed securities which are accounted for under the Fair Value Option. Such securities are reported at fair value; gains (losses) are included in earnings.

No definition available.

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