Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0001140361-23-020912-index-headers.html | 2023-04-27 16:04:45 | |
| 0001140361-23-020912-index.html | 2023-04-27 16:04:45 | |
| 0001140361-23-020912.txt | 2023-04-27 16:04:45 | |
 0001140361-23-020912-xbrl.zip | 402424 | 2023-04-27 16:04:45 |
| brhc20051583_20f.htm | 1964564 | 2023-04-27 16:04:45 |
| brhc20051583_20f_htm.xml | 875037 | 2023-04-27 16:04:45 |
| brhc20051583_ex12-1.htm | 5936 | 2023-04-27 16:04:45 |
| brhc20051583_ex12-2.htm | 6032 | 2023-04-27 16:04:45 |
| brhc20051583_ex13-1.htm | 3741 | 2023-04-27 16:04:45 |
| brhc20051583_ex13-2.htm | 3748 | 2023-04-27 16:04:45 |
| brhc20051583_ex15-1.htm | 1662 | 2023-04-27 16:04:45 |
| brhc20051583_ex15-2.htm | 8631 | 2023-04-27 16:04:45 |
| brhc20051583_ex4-11.htm | 137119 | 2023-04-27 16:04:45 |
| brhc20051583_ex8-1.htm | 3635 | 2023-04-27 16:04:45 |
| FilingSummary.xml | 33867 | 2023-04-27 16:04:45 |
| Financial_Report.xlsx | 92508 | 2023-04-27 16:04:45 |
 image00001.jpg | 40439 | 2023-04-27 16:04:45 |
 image00003.jpg | 3732 | 2023-04-27 16:04:45 |
 image00004.jpg | 4678 | 2023-04-27 16:04:45 |
| MetaLinks.json | 658863 | 2023-04-27 16:04:45 |
| nat-20221231.xsd | 60714 | 2023-04-27 16:04:45 |
| nat-20221231_cal.xml | 57178 | 2023-04-27 16:04:45 |
| nat-20221231_def.xml | 220228 | 2023-04-27 16:04:45 |
| nat-20221231_lab.xml | 739735 | 2023-04-27 16:04:45 |
| nat-20221231_pre.xml | 382619 | 2023-04-27 16:04:45 |
| R1.htm | 68866 | 2023-04-27 16:04:45 |
| R10.htm | 33885 | 2023-04-27 16:04:45 |
| R11.htm | 24375 | 2023-04-27 16:04:45 |
| R12.htm | 32473 | 2023-04-27 16:04:45 |
| R13.htm | 6791 | 2023-04-27 16:04:45 |
| R14.htm | 12362 | 2023-04-27 16:04:45 |
| R15.htm | 18248 | 2023-04-27 16:04:45 |
| R16.htm | 47034 | 2023-04-27 16:04:45 |
| R17.htm | 15176 | 2023-04-27 16:04:45 |
| R18.htm | 13346 | 2023-04-27 16:04:45 |
| R19.htm | 26406 | 2023-04-27 16:04:45 |
| R2.htm | 73962 | 2023-04-27 16:04:45 |
| R20.htm | 43307 | 2023-04-27 16:04:45 |
| R21.htm | 7369 | 2023-04-27 16:04:45 |
| R22.htm | 39884 | 2023-04-27 16:04:45 |
| R23.htm | 5855 | 2023-04-27 16:04:45 |
| R24.htm | 83130 | 2023-04-27 16:04:45 |
| R25.htm | 17593 | 2023-04-27 16:04:45 |
| R26.htm | 22251 | 2023-04-27 16:04:45 |
| R27.htm | 26597 | 2023-04-27 16:04:45 |
| R28.htm | 12086 | 2023-04-27 16:04:45 |
| R29.htm | 12632 | 2023-04-27 16:04:45 |
| R3.htm | 30400 | 2023-04-27 16:04:45 |
| R30.htm | 29344 | 2023-04-27 16:04:45 |
| R31.htm | 13780 | 2023-04-27 16:04:45 |
| R32.htm | 12185 | 2023-04-27 16:04:45 |
| R33.htm | 24666 | 2023-04-27 16:04:45 |
| R34.htm | 30096 | 2023-04-27 16:04:45 |
| R35.htm | 33282 | 2023-04-27 16:04:45 |
| R36.htm | 52209 | 2023-04-27 16:04:45 |
| R37.htm | 4397 | 2023-04-27 16:04:45 |
| R38.htm | 12675 | 2023-04-27 16:04:45 |
| R39.htm | 5912 | 2023-04-27 16:04:45 |
| R4.htm | 115297 | 2023-04-27 16:04:45 |
| R40.htm | 6396 | 2023-04-27 16:04:45 |
| R41.htm | 13381 | 2023-04-27 16:04:45 |
| R42.htm | 28348 | 2023-04-27 16:04:45 |
| R43.htm | 31135 | 2023-04-27 16:04:45 |
| R44.htm | 48588 | 2023-04-27 16:04:45 |
| R45.htm | 11766 | 2023-04-27 16:04:45 |
| R46.htm | 10499 | 2023-04-27 16:04:45 |
| R47.htm | 54421 | 2023-04-27 16:04:45 |
| R48.htm | 149013 | 2023-04-27 16:04:45 |
| R49.htm | 12259 | 2023-04-27 16:04:45 |
| R5.htm | 10807 | 2023-04-27 16:04:45 |
| R50.htm | 10744 | 2023-04-27 16:04:45 |
| R51.htm | 37239 | 2023-04-27 16:04:45 |
| R52.htm | 136540 | 2023-04-27 16:04:45 |
| R53.htm | 6225 | 2023-04-27 16:04:45 |
| R54.htm | 35809 | 2023-04-27 16:04:45 |
| R55.htm | 10990 | 2023-04-27 16:04:45 |
| R6.htm | 53093 | 2023-04-27 16:04:45 |
| R7.htm | 4551 | 2023-04-27 16:04:45 |
| R8.htm | 101717 | 2023-04-27 16:04:45 |
| R9.htm | 21269 | 2023-04-27 16:04:45 |
| report.css | 2767 | 2023-04-27 16:04:45 |
| Show.js | 1085 | 2023-04-27 16:04:45 |