Deposits (Details Textual) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Time Deposits 250000 Or More	$ 24.8	$ 26.1

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