Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0001031203-21-000007-index-headers.html | 2021-02-24 12:44:50 | |
| 0001031203-21-000007-index.html | 2021-02-24 12:44:50 | |
| 0001031203-21-000007.txt | 2021-02-24 12:44:50 | |
 0001031203-21-000007-xbrl.zip | 680213 | 2021-02-24 12:44:50 |
| a2020ex211-subsidiariesofg.htm | 128732 | 2021-02-24 12:44:50 |
| a2020exhibit1049.htm | 45547 | 2021-02-24 12:44:50 |
| a2020exhibit231.htm | 2199 | 2021-02-24 12:44:50 |
| a2020exhibit232.htm | 3513 | 2021-02-24 12:44:50 |
| a2020exhibit311.htm | 9831 | 2021-02-24 12:44:50 |
| a2020exhibit312.htm | 9883 | 2021-02-24 12:44:50 |
| a2020exhibit321.htm | 5041 | 2021-02-24 12:44:50 |
| a2020exhibit322.htm | 5022 | 2021-02-24 12:44:50 |
| a2020exhibit48.htm | 29982 | 2021-02-24 12:44:50 |
| FilingSummary.xml | 64899 | 2021-02-24 12:44:50 |
| Financial_Report.xlsx | 157536 | 2021-02-24 12:44:50 |
| gpi-20201231.htm | 3846472 | 2021-02-24 12:44:50 |
| gpi-20201231.xsd | 89852 | 2021-02-24 12:44:50 |
| gpi-20201231_cal.xml | 160484 | 2021-02-24 12:44:50 |
| gpi-20201231_def.xml | 429862 | 2021-02-24 12:44:50 |
 gpi-20201231_g1.jpg | 70582 | 2021-02-24 12:44:50 |
 gpi-20201231_g2.jpg | 89143 | 2021-02-24 12:44:50 |
 gpi-20201231_g3.jpg | 89533 | 2021-02-24 12:44:50 |
| gpi-20201231_htm.xml | 2793246 | 2021-02-24 12:44:50 |
| gpi-20201231_lab.xml | 970070 | 2021-02-24 12:44:50 |
| gpi-20201231_pre.xml | 693563 | 2021-02-24 12:44:50 |
 image_21.jpg | 36554 | 2021-02-24 12:44:50 |
| MetaLinks.json | 896306 | 2021-02-24 12:44:50 |
| R1.htm | 64807 | 2021-02-24 12:44:50 |
| R10.htm | 61541 | 2021-02-24 12:44:50 |
| R100.htm | 60740 | 2021-02-24 12:44:50 |
| R101.htm | 15643 | 2021-02-24 12:44:50 |
| R102.htm | 4112 | 2021-02-24 12:44:50 |
| R103.htm | 66849 | 2021-02-24 12:44:50 |
| R104.htm | 18207 | 2021-02-24 12:44:50 |
| R11.htm | 81614 | 2021-02-24 12:44:50 |
| R12.htm | 10413 | 2021-02-24 12:44:50 |
| R13.htm | 38271 | 2021-02-24 12:44:50 |
| R14.htm | 29221 | 2021-02-24 12:44:50 |
| R15.htm | 55309 | 2021-02-24 12:44:50 |
| R16.htm | 30531 | 2021-02-24 12:44:50 |
| R17.htm | 15554 | 2021-02-24 12:44:50 |
| R18.htm | 20352 | 2021-02-24 12:44:50 |
| R19.htm | 147437 | 2021-02-24 12:44:50 |
| R2.htm | 83796 | 2021-02-24 12:44:50 |
| R20.htm | 53408 | 2021-02-24 12:44:50 |
| R21.htm | 28994 | 2021-02-24 12:44:50 |
| R22.htm | 44170 | 2021-02-24 12:44:50 |
| R23.htm | 103563 | 2021-02-24 12:44:50 |
| R24.htm | 7868 | 2021-02-24 12:44:50 |
| R25.htm | 7562 | 2021-02-24 12:44:50 |
| R26.htm | 67663 | 2021-02-24 12:44:50 |
| R27.htm | 9190 | 2021-02-24 12:44:50 |
| R28.htm | 133341 | 2021-02-24 12:44:50 |
| R29.htm | 86930 | 2021-02-24 12:44:50 |
| R3.htm | 26521 | 2021-02-24 12:44:50 |
| R30.htm | 28931 | 2021-02-24 12:44:50 |
| R31.htm | 70711 | 2021-02-24 12:44:50 |
| R32.htm | 27113 | 2021-02-24 12:44:50 |
| R33.htm | 28756 | 2021-02-24 12:44:50 |
| R34.htm | 47641 | 2021-02-24 12:44:50 |
| R35.htm | 28235 | 2021-02-24 12:44:50 |
| R36.htm | 14555 | 2021-02-24 12:44:50 |
| R37.htm | 22505 | 2021-02-24 12:44:50 |
| R38.htm | 88715 | 2021-02-24 12:44:50 |
| R39.htm | 45733 | 2021-02-24 12:44:50 |
| R4.htm | 56889 | 2021-02-24 12:44:50 |
| R40.htm | 20651 | 2021-02-24 12:44:50 |
| R41.htm | 43692 | 2021-02-24 12:44:50 |
| R42.htm | 103609 | 2021-02-24 12:44:50 |
| R43.htm | 67516 | 2021-02-24 12:44:50 |
| R44.htm | 134556 | 2021-02-24 12:44:50 |
| R45.htm | 12301 | 2021-02-24 12:44:50 |
| R46.htm | 15445 | 2021-02-24 12:44:50 |
| R47.htm | 4599 | 2021-02-24 12:44:50 |
| R48.htm | 21808 | 2021-02-24 12:44:50 |
| R49.htm | 31082 | 2021-02-24 12:44:50 |
| R5.htm | 37164 | 2021-02-24 12:44:50 |
| R50.htm | 5288 | 2021-02-24 12:44:50 |
| R51.htm | 6474 | 2021-02-24 12:44:50 |
| R52.htm | 12682 | 2021-02-24 12:44:50 |
| R53.htm | 4008 | 2021-02-24 12:44:50 |
| R54.htm | 4214 | 2021-02-24 12:44:50 |
| R55.htm | 4596 | 2021-02-24 12:44:50 |
| R56.htm | 17610 | 2021-02-24 12:44:50 |
| R57.htm | 48108 | 2021-02-24 12:44:50 |
| R58.htm | 10151 | 2021-02-24 12:44:50 |
| R59.htm | 33263 | 2021-02-24 12:44:50 |
| R6.htm | 13759 | 2021-02-24 12:44:50 |
| R60.htm | 64916 | 2021-02-24 12:44:50 |
| R61.htm | 24782 | 2021-02-24 12:44:50 |
| R62.htm | 15699 | 2021-02-24 12:44:50 |
| R63.htm | 20151 | 2021-02-24 12:44:50 |
| R64.htm | 34574 | 2021-02-24 12:44:50 |
| R65.htm | 42769 | 2021-02-24 12:44:50 |
| R66.htm | 15195 | 2021-02-24 12:44:50 |
| R67.htm | 18240 | 2021-02-24 12:44:50 |
| R68.htm | 18647 | 2021-02-24 12:44:50 |
| R69.htm | 35512 | 2021-02-24 12:44:50 |
| R7.htm | 42113 | 2021-02-24 12:44:50 |
| R70.htm | 10676 | 2021-02-24 12:44:50 |
| R71.htm | 9033 | 2021-02-24 12:44:50 |
| R72.htm | 21151 | 2021-02-24 12:44:50 |
| R73.htm | 13537 | 2021-02-24 12:44:50 |
| R74.htm | 20107 | 2021-02-24 12:44:50 |
| R75.htm | 20300 | 2021-02-24 12:44:50 |
| R76.htm | 19568 | 2021-02-24 12:44:50 |
| R77.htm | 38543 | 2021-02-24 12:44:50 |
| R78.htm | 11668 | 2021-02-24 12:44:50 |
| R79.htm | 19341 | 2021-02-24 12:44:50 |
| R8.htm | 4659 | 2021-02-24 12:44:50 |
| R80.htm | 30948 | 2021-02-24 12:44:50 |
| R81.htm | 10981 | 2021-02-24 12:44:50 |
| R82.htm | 29603 | 2021-02-24 12:44:50 |
| R83.htm | 23127 | 2021-02-24 12:44:50 |
| R84.htm | 71472 | 2021-02-24 12:44:50 |
| R85.htm | 42477 | 2021-02-24 12:44:50 |
| R86.htm | 19182 | 2021-02-24 12:44:50 |
| R87.htm | 10098 | 2021-02-24 12:44:50 |
| R88.htm | 38132 | 2021-02-24 12:44:50 |
| R89.htm | 9371 | 2021-02-24 12:44:50 |
| R9.htm | 100567 | 2021-02-24 12:44:50 |
| R90.htm | 15563 | 2021-02-24 12:44:50 |
| R91.htm | 9223 | 2021-02-24 12:44:50 |
| R92.htm | 23578 | 2021-02-24 12:44:50 |
| R93.htm | 24993 | 2021-02-24 12:44:50 |
| R94.htm | 29674 | 2021-02-24 12:44:50 |
| R95.htm | 40294 | 2021-02-24 12:44:50 |
| R96.htm | 16227 | 2021-02-24 12:44:50 |
| R97.htm | 8861 | 2021-02-24 12:44:50 |
| R98.htm | 13270 | 2021-02-24 12:44:50 |
| R99.htm | 5811 | 2021-02-24 12:44:50 |
| R9999.htm | 2931 | 2021-02-24 12:44:50 |
| report.css | 2768 | 2021-02-24 12:44:50 |
| Show.js | 1086 | 2021-02-24 12:44:50 |