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| 0000104889-18-000020-index.html | 2018-05-02 08:56:00 | |
| 0000104889-18-000020.txt | 2018-05-02 08:56:00 | |
 0000104889-18-000020-xbrl.zip | 384532 | 2018-05-02 08:56:00 |
| d10q.htm | 1550004 | 2018-05-02 08:56:00 |
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| dex32.htm | 6375 | 2018-05-02 08:56:00 |
| FilingSummary.xml | 48494 | 2018-05-02 08:56:00 |
| Financial_Report.xlsx | 113435 | 2018-05-02 08:56:00 |
| ghc-20180331.xml | 3343242 | 2018-05-02 08:56:00 |
| ghc-20180331.xsd | 92316 | 2018-05-02 08:56:00 |
| ghc-20180331_cal.xml | 158134 | 2018-05-02 08:56:00 |
| ghc-20180331_def.xml | 618807 | 2018-05-02 08:56:00 |
| ghc-20180331_lab.xml | 1183085 | 2018-05-02 08:56:00 |
| ghc-20180331_pre.xml | 796403 | 2018-05-02 08:56:00 |
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| report.css | 2767 | 2018-05-02 08:56:00 |
| Show.js | 1410 | 2018-05-02 08:56:00 |