XML 68 R53.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Accumulated Other Comprehensive Loss (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2018
Components of Accumulated Other Comprehensive Income (Loss) [Abstract] |
Schedule of Accumulated Other Comprehensive Income (Loss) | The following table displays the activity of Accumulated Other Comprehensive Loss, net of tax:
(in millions) | Gains and Losses on Securities(1) |  | Gains and Losses on Cash Flow Hedges(1) |  | Pension and OPEB Items(1) |  | Accumulated Other Comprehensive Loss(1)
Balance as of January 1, 2016 | $ | (0.5 | ) |  | $ | (15.5 | ) |  | $ | (19.1 | ) |  | $ | (35.1 | )
Other comprehensive loss before reclassifications | — |  |  | 7.1 |  |  | 0.5 |  |  | 7.6 |
Amounts reclassified from accumulated other comprehensive loss | (0.1 | ) |  | 1.5 |  |  | 1.0 |  |  | 2.4 |
Net current-period other comprehensive loss | (0.1 | ) |  | 8.6 |  |  | 1.5 |  |  | 10.0 |
Balance as of December 31, 2016 | $ | (0.6 | ) |  | $ | (6.9 | ) |  | $ | (17.6 | ) |  | $ | (25.1 | )
Other comprehensive income before reclassifications | 0.6 |  |  | (24.2 | ) |  | 1.9 |  |  | (21.7 | )
Amounts reclassified from accumulated other comprehensive loss | 0.2 |  |  | 1.7 |  |  | 1.5 |  |  | 3.4 |
Net current-period other comprehensive income (loss) | 0.8 |  |  | (22.5 | ) |  | 3.4 |  |  | (18.3 | )
Balance as of December 31, 2017 | $ | 0.2 |  |  | $ | (29.4 | ) |  | $ | (14.2 | ) |  | $ | (43.4 | )
Other comprehensive income (loss) before reclassifications | (3.0 | ) |  | 55.8 |  |  | (4.4 | ) |  | 48.4 |
Amounts reclassified from accumulated other comprehensive loss | 0.4 |  |  | (33.1 | ) |  | — |  |  | (32.7 | )
Net current-period other comprehensive income (loss) | (2.6 | ) |  | 22.7 |  |  | (4.4 | ) |  | 15.7 |
Reclassification due to adoption of ASU 2018-02 (Refer to Note 2) | — |  |  | (6.3 | ) |  | (3.2 | ) |  | (9.5 | )
Balance as of December 31, 2018 | $ | (2.4 | ) |  | $ | (13.0 | ) |  | $ | (21.8 | ) |  | $ | (37.2 | )
(1)All amounts are net of tax. Amounts in parentheses indicate debits.

X
- Definition Components of Accumulated Other Comprehensive Income (Loss) [Abstract] + References No definition available. + Details
Name: | nix_ComponentsofAccumulatedOtherComprehensiveIncomeLossAbstract
Namespace Prefix: | nix_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the components of accumulated other comprehensive income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669686-108580 + Details
Name: | us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration