Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0001628280-21-022420-index-headers.html | 2021-11-09 09:18:41 | |
| 0001628280-21-022420-index.html | 2021-11-09 09:18:41 | |
| 0001628280-21-022420.txt | 2021-11-09 09:18:41 | |
 0001628280-21-022420-xbrl.zip | 270562 | 2021-11-09 09:18:41 |
| exhibit10110-q2021q3.htm | 33894 | 2021-11-09 09:18:41 |
| exhibit31110-qfy2021q3.htm | 10081 | 2021-11-09 09:18:41 |
| exhibit31210-qfy2021q3.htm | 10039 | 2021-11-09 09:18:41 |
| exhibit32110-qfy2021q3.htm | 5806 | 2021-11-09 09:18:41 |
| FilingSummary.xml | 31663 | 2021-11-09 09:18:41 |
| Financial_Report.xlsx | 74053 | 2021-11-09 09:18:41 |
| MetaLinks.json | 526496 | 2021-11-09 09:18:41 |
| mrsn-20210930.htm | 1443972 | 2021-11-09 09:18:41 |
| mrsn-20210930.xsd | 44350 | 2021-11-09 09:18:41 |
| mrsn-20210930_cal.xml | 58112 | 2021-11-09 09:18:41 |
| mrsn-20210930_def.xml | 204498 | 2021-11-09 09:18:41 |
| mrsn-20210930_htm.xml | 866266 | 2021-11-09 09:18:41 |
| mrsn-20210930_lab.xml | 528461 | 2021-11-09 09:18:41 |
| mrsn-20210930_pre.xml | 355468 | 2021-11-09 09:18:41 |
| R1.htm | 52178 | 2021-11-09 09:18:41 |
| R10.htm | 38363 | 2021-11-09 09:18:41 |
| R11.htm | 5285 | 2021-11-09 09:18:41 |
| R12.htm | 13996 | 2021-11-09 09:18:41 |
| R13.htm | 21629 | 2021-11-09 09:18:41 |
| R14.htm | 20033 | 2021-11-09 09:18:41 |
| R15.htm | 60423 | 2021-11-09 09:18:41 |
| R16.htm | 35984 | 2021-11-09 09:18:41 |
| R17.htm | 5949 | 2021-11-09 09:18:41 |
| R18.htm | 6236 | 2021-11-09 09:18:41 |
| R19.htm | 32722 | 2021-11-09 09:18:41 |
| R2.htm | 94292 | 2021-11-09 09:18:41 |
| R20.htm | 37279 | 2021-11-09 09:18:41 |
| R21.htm | 30284 | 2021-11-09 09:18:41 |
| R22.htm | 14168 | 2021-11-09 09:18:41 |
| R23.htm | 15499 | 2021-11-09 09:18:41 |
| R24.htm | 14480 | 2021-11-09 09:18:41 |
| R25.htm | 62317 | 2021-11-09 09:18:41 |
| R26.htm | 28025 | 2021-11-09 09:18:41 |
| R27.htm | 19739 | 2021-11-09 09:18:41 |
| R28.htm | 12023 | 2021-11-09 09:18:41 |
| R29.htm | 8394 | 2021-11-09 09:18:41 |
| R3.htm | 19637 | 2021-11-09 09:18:41 |
| R30.htm | 13201 | 2021-11-09 09:18:41 |
| R31.htm | 13177 | 2021-11-09 09:18:41 |
| R32.htm | 29860 | 2021-11-09 09:18:41 |
| R33.htm | 20662 | 2021-11-09 09:18:41 |
| R34.htm | 14575 | 2021-11-09 09:18:41 |
| R35.htm | 17773 | 2021-11-09 09:18:41 |
| R36.htm | 31968 | 2021-11-09 09:18:41 |
| R37.htm | 18396 | 2021-11-09 09:18:41 |
| R38.htm | 15773 | 2021-11-09 09:18:41 |
| R39.htm | 6948 | 2021-11-09 09:18:41 |
| R4.htm | 74282 | 2021-11-09 09:18:41 |
| R40.htm | 27691 | 2021-11-09 09:18:41 |
| R41.htm | 10098 | 2021-11-09 09:18:41 |
| R42.htm | 15406 | 2021-11-09 09:18:41 |
| R43.htm | 13811 | 2021-11-09 09:18:41 |
| R44.htm | 31032 | 2021-11-09 09:18:41 |
| R45.htm | 7245 | 2021-11-09 09:18:41 |
| R46.htm | 33594 | 2021-11-09 09:18:41 |
| R47.htm | 20602 | 2021-11-09 09:18:41 |
| R48.htm | 23300 | 2021-11-09 09:18:41 |
| R49.htm | 12721 | 2021-11-09 09:18:41 |
| R5.htm | 125843 | 2021-11-09 09:18:41 |
| R50.htm | 17203 | 2021-11-09 09:18:41 |
| R51.htm | 31669 | 2021-11-09 09:18:41 |
| R52.htm | 35384 | 2021-11-09 09:18:41 |
| R53.htm | 7044 | 2021-11-09 09:18:41 |
| R54.htm | 26826 | 2021-11-09 09:18:41 |
| R6.htm | 7480 | 2021-11-09 09:18:41 |
| R7.htm | 89313 | 2021-11-09 09:18:41 |
| R8.htm | 12660 | 2021-11-09 09:18:41 |
| R9.htm | 31729 | 2021-11-09 09:18:41 |
| report.css | 2767 | 2021-11-09 09:18:41 |
| Show.js | 1085 | 2021-11-09 09:18:41 |