Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000110019-24-000003-index-headers.html | 2024-02-21 16:11:51 | |
| 0000110019-24-000003-index.html | 2024-02-21 16:11:51 | |
| 0000110019-24-000003.txt | 2024-02-21 16:11:51 | |
 0000110019-24-000003-xbrl.zip | 190118 | 2024-02-21 16:11:51 |
| FilingSummary.xml | 23378 | 2024-02-21 16:11:51 |
| Financial_Report.xlsx | 73398 | 2024-02-21 16:11:51 |
| MetaLinks.json | 546142 | 2024-02-21 16:11:51 |
| nwp-20231231.htm | 914184 | 2024-02-21 16:11:51 |
| nwp-20231231.xsd | 29709 | 2024-02-21 16:11:51 |
| nwp-20231231_cal.xml | 53827 | 2024-02-21 16:11:51 |
| nwp-20231231_def.xml | 184054 | 2024-02-21 16:11:51 |
| nwp-20231231_htm.xml | 558906 | 2024-02-21 16:11:51 |
| nwp-20231231_lab.xml | 440374 | 2024-02-21 16:11:51 |
| nwp-20231231_pre.xml | 272426 | 2024-02-21 16:11:51 |
| nwp_20231231xex-311.htm | 10164 | 2024-02-21 16:11:51 |
| nwp_20231231xex-312.htm | 10407 | 2024-02-21 16:11:51 |
| nwp_20231231xex-32.htm | 6423 | 2024-02-21 16:11:51 |
| R1.htm | 55858 | 2024-02-21 16:11:51 |
| R10.htm | 4862 | 2024-02-21 16:11:51 |
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| R19.htm | 6543 | 2024-02-21 16:11:51 |
| R2.htm | 7786 | 2024-02-21 16:11:51 |
| R20.htm | 18781 | 2024-02-21 16:11:51 |
| R21.htm | 30385 | 2024-02-21 16:11:51 |
| R22.htm | 34944 | 2024-02-21 16:11:51 |
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| R24.htm | 12784 | 2024-02-21 16:11:51 |
| R25.htm | 11861 | 2024-02-21 16:11:51 |
| R26.htm | 31143 | 2024-02-21 16:11:51 |
| R27.htm | 54477 | 2024-02-21 16:11:51 |
| R28.htm | 7594 | 2024-02-21 16:11:51 |
| R29.htm | 9448 | 2024-02-21 16:11:51 |
| R3.htm | 60158 | 2024-02-21 16:11:51 |
| R30.htm | 46493 | 2024-02-21 16:11:51 |
| R31.htm | 42418 | 2024-02-21 16:11:51 |
| R32.htm | 5313 | 2024-02-21 16:11:51 |
| R33.htm | 31318 | 2024-02-21 16:11:51 |
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| R35.htm | 18518 | 2024-02-21 16:11:51 |
| R36.htm | 9216 | 2024-02-21 16:11:51 |
| R37.htm | 38742 | 2024-02-21 16:11:51 |
| R38.htm | 9828 | 2024-02-21 16:11:51 |
| R39.htm | 37389 | 2024-02-21 16:11:51 |
| R4.htm | 118238 | 2024-02-21 16:11:51 |
| R5.htm | 21131 | 2024-02-21 16:11:51 |
| R6.htm | 81457 | 2024-02-21 16:11:51 |
| R7.htm | 55566 | 2024-02-21 16:11:51 |
| R8.htm | 35641 | 2024-02-21 16:11:51 |
| R9.htm | 33188 | 2024-02-21 16:11:51 |
| report.css | 2767 | 2024-02-21 16:11:51 |
| Show.js | 1085 | 2024-02-21 16:11:51 |