Offsetting Assets and Liabilities (Details Textual) (Minimum [Member])	Jun. 28, 2013
U.S. [Member]
Offsetting Assets and Liabilities (Textual) [Abstract]
Actual collateral of related assets	102.00%
Canada [Member]
Offsetting Assets and Liabilities (Textual) [Abstract]
Actual collateral of related assets	100.00%

Collateral related to securities purchased under agreements to resell percentage.

No definition available.

Name:	jnfc_ActualCollateralPercentageOfRelatedAssetValues
Namespace Prefix:	jnfc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant