Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0001564590-21-024496-index-headers.html | 2021-05-06 07:00:50 | |
| 0001564590-21-024496-index.html | 2021-05-06 07:00:50 | |
| 0001564590-21-024496.txt | 2021-05-06 07:00:50 | |
 0001564590-21-024496-xbrl.zip | 188843 | 2021-05-06 07:00:50 |
| FilingSummary.xml | 39766 | 2021-05-06 07:00:50 |
| Financial_Report.xlsx | 89808 | 2021-05-06 07:00:50 |
| hmhc-10q_20210331.htm | 2098680 | 2021-05-06 07:00:50 |
| hmhc-10q_20210331_htm.xml | 1563939 | 2021-05-06 07:00:50 |
| hmhc-20210331.xsd | 51934 | 2021-05-06 07:00:50 |
| hmhc-20210331_cal.xml | 78580 | 2021-05-06 07:00:50 |
| hmhc-20210331_def.xml | 235564 | 2021-05-06 07:00:50 |
| hmhc-20210331_lab.xml | 457395 | 2021-05-06 07:00:50 |
| hmhc-20210331_pre.xml | 377241 | 2021-05-06 07:00:50 |
| hmhc-ex311_10.htm | 13519 | 2021-05-06 07:00:50 |
| hmhc-ex312_6.htm | 13531 | 2021-05-06 07:00:50 |
| hmhc-ex321_8.htm | 7268 | 2021-05-06 07:00:50 |
| hmhc-ex322_7.htm | 7368 | 2021-05-06 07:00:50 |
| MetaLinks.json | 691498 | 2021-05-06 07:00:50 |
| R1.htm | 52221 | 2021-05-06 07:00:50 |
| R10.htm | 6863 | 2021-05-06 07:00:50 |
| R11.htm | 17997 | 2021-05-06 07:00:50 |
| R12.htm | 100510 | 2021-05-06 07:00:50 |
| R13.htm | 20236 | 2021-05-06 07:00:50 |
| R14.htm | 57832 | 2021-05-06 07:00:50 |
| R15.htm | 69413 | 2021-05-06 07:00:50 |
| R16.htm | 49938 | 2021-05-06 07:00:50 |
| R17.htm | 73360 | 2021-05-06 07:00:50 |
| R18.htm | 10415 | 2021-05-06 07:00:50 |
| R19.htm | 61988 | 2021-05-06 07:00:50 |
| R2.htm | 129654 | 2021-05-06 07:00:50 |
| R20.htm | 159606 | 2021-05-06 07:00:50 |
| R21.htm | 15127 | 2021-05-06 07:00:50 |
| R22.htm | 67227 | 2021-05-06 07:00:50 |
| R23.htm | 10764 | 2021-05-06 07:00:50 |
| R24.htm | 101370 | 2021-05-06 07:00:50 |
| R25.htm | 20292 | 2021-05-06 07:00:50 |
| R26.htm | 54041 | 2021-05-06 07:00:50 |
| R27.htm | 67007 | 2021-05-06 07:00:50 |
| R28.htm | 31266 | 2021-05-06 07:00:50 |
| R29.htm | 69960 | 2021-05-06 07:00:50 |
| R3.htm | 23806 | 2021-05-06 07:00:50 |
| R30.htm | 54868 | 2021-05-06 07:00:50 |
| R31.htm | 142831 | 2021-05-06 07:00:50 |
| R32.htm | 67390 | 2021-05-06 07:00:50 |
| R33.htm | 16863 | 2021-05-06 07:00:50 |
| R34.htm | 36981 | 2021-05-06 07:00:50 |
| R35.htm | 13745 | 2021-05-06 07:00:50 |
| R36.htm | 13485 | 2021-05-06 07:00:50 |
| R37.htm | 28542 | 2021-05-06 07:00:50 |
| R38.htm | 46020 | 2021-05-06 07:00:50 |
| R39.htm | 9521 | 2021-05-06 07:00:50 |
| R4.htm | 76489 | 2021-05-06 07:00:50 |
| R40.htm | 15740 | 2021-05-06 07:00:50 |
| R41.htm | 22373 | 2021-05-06 07:00:50 |
| R42.htm | 4892 | 2021-05-06 07:00:50 |
| R43.htm | 15342 | 2021-05-06 07:00:50 |
| R44.htm | 16221 | 2021-05-06 07:00:50 |
| R45.htm | 22875 | 2021-05-06 07:00:50 |
| R46.htm | 21384 | 2021-05-06 07:00:50 |
| R47.htm | 13387 | 2021-05-06 07:00:50 |
| R48.htm | 81876 | 2021-05-06 07:00:50 |
| R49.htm | 27344 | 2021-05-06 07:00:50 |
| R5.htm | 26425 | 2021-05-06 07:00:50 |
| R50.htm | 18836 | 2021-05-06 07:00:50 |
| R51.htm | 10383 | 2021-05-06 07:00:50 |
| R52.htm | 10069 | 2021-05-06 07:00:50 |
| R53.htm | 29360 | 2021-05-06 07:00:50 |
| R54.htm | 22236 | 2021-05-06 07:00:50 |
| R55.htm | 41954 | 2021-05-06 07:00:50 |
| R56.htm | 12123 | 2021-05-06 07:00:50 |
| R57.htm | 12128 | 2021-05-06 07:00:50 |
| R58.htm | 27637 | 2021-05-06 07:00:50 |
| R59.htm | 31056 | 2021-05-06 07:00:50 |
| R6.htm | 111412 | 2021-05-06 07:00:50 |
| R60.htm | 9313 | 2021-05-06 07:00:50 |
| R7.htm | 43712 | 2021-05-06 07:00:50 |
| R8.htm | 15342 | 2021-05-06 07:00:50 |
| R9.htm | 19809 | 2021-05-06 07:00:50 |
| report.css | 2767 | 2021-05-06 07:00:50 |
| Show.js | 1085 | 2021-05-06 07:00:50 |