Deposits (Details Textual) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Time Deposits 250000 Or More	$ 20,919,000	$ 21,108,000

The aggregate amount of domestic and foreign time deposit liabilities (including certificates of deposits, individual retirement accounts and open accounts) in denominations of $250,000 or more.

No definition available.

Name:	nwin_TimeDeposits250000OrMore
Namespace Prefix:	nwin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant