Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000104889-18-000011-index-headers.html | 2018-02-23 16:59:48 | |
| 0000104889-18-000011-index.html | 2018-02-23 16:59:48 | |
| 0000104889-18-000011.txt | 2018-02-23 16:59:48 | |
 0000104889-18-000011-xbrl.zip | 694307 | 2018-02-23 16:59:48 |
| a2017q4ex109.htm | 5650 | 2018-02-23 16:59:48 |
| d2017q410k.htm | 3609398 | 2018-02-23 16:59:48 |
| d2017q4ex21.htm | 299626 | 2018-02-23 16:59:48 |
| d2017q4ex23.htm | 2937 | 2018-02-23 16:59:48 |
| d2017q4ex24.htm | 14175 | 2018-02-23 16:59:48 |
| d2017q4ex312.htm | 9846 | 2018-02-23 16:59:48 |
| d2017q4ex32.htm | 6805 | 2018-02-23 16:59:48 |
| d2107q4ex311.htm | 9859 | 2018-02-23 16:59:48 |
| FilingSummary.xml | 76711 | 2018-02-23 16:59:48 |
| Financial_Report.xlsx | 215981 | 2018-02-23 16:59:48 |
| ghc-20171231.xml | 5922496 | 2018-02-23 16:59:48 |
| ghc-20171231.xsd | 151206 | 2018-02-23 16:59:48 |
| ghc-20171231_cal.xml | 245939 | 2018-02-23 16:59:48 |
| ghc-20171231_def.xml | 1111041 | 2018-02-23 16:59:48 |
| ghc-20171231_lab.xml | 2026695 | 2018-02-23 16:59:48 |
| ghc-20171231_pre.xml | 1386067 | 2018-02-23 16:59:48 |
 ghcgraph2017a01.jpg | 48327 | 2018-02-23 16:59:48 |
| R1.htm | 33971 | 2018-02-23 16:59:48 |
| R10.htm | 76546 | 2018-02-23 16:59:48 |
| R100.htm | 47721 | 2018-02-23 16:59:48 |
| R101.htm | 12702 | 2018-02-23 16:59:48 |
| R102.htm | 12450 | 2018-02-23 16:59:48 |
| R103.htm | 50467 | 2018-02-23 16:59:48 |
| R104.htm | 31921 | 2018-02-23 16:59:48 |
| R105.htm | 62368 | 2018-02-23 16:59:48 |
| R106.htm | 37844 | 2018-02-23 16:59:48 |
| R107.htm | 73830 | 2018-02-23 16:59:48 |
| R108.htm | 13906 | 2018-02-23 16:59:48 |
| R109.htm | 19728 | 2018-02-23 16:59:48 |
| R11.htm | 49058 | 2018-02-23 16:59:48 |
| R110.htm | 66713 | 2018-02-23 16:59:48 |
| R111.htm | 68177 | 2018-02-23 16:59:48 |
| R112.htm | 16427 | 2018-02-23 16:59:48 |
| R113.htm | 116912 | 2018-02-23 16:59:48 |
| R114.htm | 5859 | 2018-02-23 16:59:48 |
| R115.htm | 116491 | 2018-02-23 16:59:48 |
| R116.htm | 55538 | 2018-02-23 16:59:48 |
| R12.htm | 21068 | 2018-02-23 16:59:48 |
| R13.htm | 36884 | 2018-02-23 16:59:48 |
| R14.htm | 15495 | 2018-02-23 16:59:48 |
| R15.htm | 22945 | 2018-02-23 16:59:48 |
| R16.htm | 203421 | 2018-02-23 16:59:48 |
| R17.htm | 194425 | 2018-02-23 16:59:48 |
| R18.htm | 34153 | 2018-02-23 16:59:48 |
| R19.htm | 90370 | 2018-02-23 16:59:48 |
| R2.htm | 107980 | 2018-02-23 16:59:48 |
| R20.htm | 5675 | 2018-02-23 16:59:48 |
| R21.htm | 147149 | 2018-02-23 16:59:48 |
| R22.htm | 422880 | 2018-02-23 16:59:48 |
| R23.htm | 34372 | 2018-02-23 16:59:48 |
| R24.htm | 222894 | 2018-02-23 16:59:48 |
| R25.htm | 15484 | 2018-02-23 16:59:48 |
| R26.htm | 30012 | 2018-02-23 16:59:48 |
| R27.htm | 248018 | 2018-02-23 16:59:48 |
| R28.htm | 233389 | 2018-02-23 16:59:48 |
| R29.htm | 160899 | 2018-02-23 16:59:48 |
| R3.htm | 65299 | 2018-02-23 16:59:48 |
| R30.htm | 26592 | 2018-02-23 16:59:48 |
| R31.htm | 56794 | 2018-02-23 16:59:48 |
| R32.htm | 46748 | 2018-02-23 16:59:48 |
| R33.htm | 13857 | 2018-02-23 16:59:48 |
| R34.htm | 40488 | 2018-02-23 16:59:48 |
| R35.htm | 16397 | 2018-02-23 16:59:48 |
| R36.htm | 19783 | 2018-02-23 16:59:48 |
| R37.htm | 196943 | 2018-02-23 16:59:48 |
| R38.htm | 183861 | 2018-02-23 16:59:48 |
| R39.htm | 21682 | 2018-02-23 16:59:48 |
| R4.htm | 116407 | 2018-02-23 16:59:48 |
| R40.htm | 86589 | 2018-02-23 16:59:48 |
| R41.htm | 125743 | 2018-02-23 16:59:48 |
| R42.htm | 434768 | 2018-02-23 16:59:48 |
| R43.htm | 28781 | 2018-02-23 16:59:48 |
| R44.htm | 227206 | 2018-02-23 16:59:48 |
| R45.htm | 11586 | 2018-02-23 16:59:48 |
| R46.htm | 238313 | 2018-02-23 16:59:48 |
| R47.htm | 234768 | 2018-02-23 16:59:48 |
| R48.htm | 10668 | 2018-02-23 16:59:48 |
| R49.htm | 30814 | 2018-02-23 16:59:48 |
| R5.htm | 21688 | 2018-02-23 16:59:48 |
| R50.htm | 27836 | 2018-02-23 16:59:48 |
| R51.htm | 24880 | 2018-02-23 16:59:48 |
| R52.htm | 175491 | 2018-02-23 16:59:48 |
| R53.htm | 34748 | 2018-02-23 16:59:48 |
| R54.htm | 6881 | 2018-02-23 16:59:48 |
| R55.htm | 9335 | 2018-02-23 16:59:48 |
| R56.htm | 88373 | 2018-02-23 16:59:48 |
| R57.htm | 60848 | 2018-02-23 16:59:48 |
| R58.htm | 30360 | 2018-02-23 16:59:48 |
| R59.htm | 83151 | 2018-02-23 16:59:48 |
| R6.htm | 114265 | 2018-02-23 16:59:48 |
| R60.htm | 8949 | 2018-02-23 16:59:48 |
| R61.htm | 5153 | 2018-02-23 16:59:48 |
| R62.htm | 29564 | 2018-02-23 16:59:48 |
| R63.htm | 13812 | 2018-02-23 16:59:48 |
| R64.htm | 22559 | 2018-02-23 16:59:48 |
| R65.htm | 21345 | 2018-02-23 16:59:48 |
| R66.htm | 27266 | 2018-02-23 16:59:48 |
| R67.htm | 39350 | 2018-02-23 16:59:48 |
| R68.htm | 74238 | 2018-02-23 16:59:48 |
| R69.htm | 56150 | 2018-02-23 16:59:48 |
| R7.htm | 103973 | 2018-02-23 16:59:48 |
| R70.htm | 139800 | 2018-02-23 16:59:48 |
| R71.htm | 12135 | 2018-02-23 16:59:48 |
| R72.htm | 37801 | 2018-02-23 16:59:48 |
| R73.htm | 42605 | 2018-02-23 16:59:48 |
| R74.htm | 54380 | 2018-02-23 16:59:48 |
| R75.htm | 26612 | 2018-02-23 16:59:48 |
| R76.htm | 10805 | 2018-02-23 16:59:48 |
| R77.htm | 16048 | 2018-02-23 16:59:48 |
| R78.htm | 154036 | 2018-02-23 16:59:48 |
| R79.htm | 24721 | 2018-02-23 16:59:48 |
| R8.htm | 7469 | 2018-02-23 16:59:48 |
| R80.htm | 11625 | 2018-02-23 16:59:48 |
| R81.htm | 47823 | 2018-02-23 16:59:48 |
| R82.htm | 21667 | 2018-02-23 16:59:48 |
| R83.htm | 221838 | 2018-02-23 16:59:48 |
| R84.htm | 24646 | 2018-02-23 16:59:48 |
| R85.htm | 27697 | 2018-02-23 16:59:48 |
| R86.htm | 41499 | 2018-02-23 16:59:48 |
| R87.htm | 25532 | 2018-02-23 16:59:48 |
| R88.htm | 49938 | 2018-02-23 16:59:48 |
| R89.htm | 6148 | 2018-02-23 16:59:48 |
| R9.htm | 76840 | 2018-02-23 16:59:48 |
| R90.htm | 126623 | 2018-02-23 16:59:48 |
| R91.htm | 57191 | 2018-02-23 16:59:48 |
| R92.htm | 22611 | 2018-02-23 16:59:48 |
| R93.htm | 17617 | 2018-02-23 16:59:48 |
| R94.htm | 22833 | 2018-02-23 16:59:48 |
| R95.htm | 67375 | 2018-02-23 16:59:48 |
| R96.htm | 25727 | 2018-02-23 16:59:48 |
| R97.htm | 23785 | 2018-02-23 16:59:48 |
| R98.htm | 13118 | 2018-02-23 16:59:48 |
| R99.htm | 15563 | 2018-02-23 16:59:48 |
| report.css | 2768 | 2018-02-23 16:59:48 |
| Show.js | 1411 | 2018-02-23 16:59:48 |