XML 53 R42.htm IDEA: XBRL DOCUMENT
v3.23.2

Revenue Recognition (Narrative) (Details) | 6 Months Ended
--- | ---
Jun. 30, 2023
Revenue from Contract with Customer [Abstract] |
Service Area By County | 20

X
- Definition Service Area By County + References No definition available. + Details
Name: | nix_ServiceAreaByCounty
Namespace Prefix: | nix_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_RevenueFromContractWithCustomerAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration