Allowance for Credit Losses Rollforward of LRA (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013
Change in Lender Risk Account Balance [Roll Forward]
Lender Risk Account, Beginning Balance	$ 102,680
Lender Risk Account, Additions	5,193
Lender Risk Account, Claims	(1,016)
Lender Risk Account, Distributions	(460)
Lender Risk Account, Ending Balance	$ 106,397

The beginning/ending balance of the period for the Lender Risk Account, which is a purchase-price holdback to cover expected credit losses for a specific pool of loans.

No definition available.

Name:	fhlbcin_LenderRiskAccountBalance
Namespace Prefix:	fhlbcin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant