Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000860546-20-000039-index-headers.html | 2020-10-30 17:12:31 | |
| 0000860546-20-000039-index.html | 2020-10-30 17:12:31 | |
| 0000860546-20-000039.txt | 2020-10-30 17:12:31 | |
 0000860546-20-000039-xbrl.zip | 545522 | 2020-10-30 17:12:31 |
| copt09302020ex311.htm | 15272 | 2020-10-30 17:12:31 |
| copt09302020ex312.htm | 15250 | 2020-10-30 17:12:31 |
| copt09302020ex313.htm | 14835 | 2020-10-30 17:12:31 |
| copt09302020ex314.htm | 14650 | 2020-10-30 17:12:31 |
| copt09302020ex321.htm | 5639 | 2020-10-30 17:12:31 |
| copt09302020ex322.htm | 5596 | 2020-10-30 17:12:31 |
| copt09302020ex323.htm | 5543 | 2020-10-30 17:12:31 |
| copt09302020ex324.htm | 5680 | 2020-10-30 17:12:31 |
| FilingSummary.xml | 48513 | 2020-10-30 17:12:31 |
| Financial_Report.xlsx | 140831 | 2020-10-30 17:12:31 |
| MetaLinks.json | 961958 | 2020-10-30 17:12:31 |
| ofc-20200930.htm | 3995939 | 2020-10-30 17:12:31 |
| ofc-20200930.xsd | 97684 | 2020-10-30 17:12:31 |
| ofc-20200930_cal.xml | 168030 | 2020-10-30 17:12:31 |
| ofc-20200930_def.xml | 612935 | 2020-10-30 17:12:31 |
| ofc-20200930_htm.xml | 3830168 | 2020-10-30 17:12:31 |
| ofc-20200930_lab.xml | 1091559 | 2020-10-30 17:12:31 |
| ofc-20200930_pre.xml | 722793 | 2020-10-30 17:12:31 |
| R1.htm | 65540 | 2020-10-30 17:12:31 |
| R10.htm | 78964 | 2020-10-30 17:12:31 |
| R11.htm | 52813 | 2020-10-30 17:12:31 |
| R12.htm | 12407 | 2020-10-30 17:12:31 |
| R13.htm | 326878 | 2020-10-30 17:12:31 |
| R14.htm | 33957 | 2020-10-30 17:12:31 |
| R15.htm | 13642 | 2020-10-30 17:12:31 |
| R16.htm | 20510 | 2020-10-30 17:12:31 |
| R17.htm | 62902 | 2020-10-30 17:12:31 |
| R18.htm | 73536 | 2020-10-30 17:12:31 |
| R19.htm | 14755 | 2020-10-30 17:12:31 |
| R2.htm | 127915 | 2020-10-30 17:12:31 |
| R20.htm | 6891 | 2020-10-30 17:12:31 |
| R21.htm | 284864 | 2020-10-30 17:12:31 |
| R22.htm | 54617 | 2020-10-30 17:12:31 |
| R23.htm | 18338 | 2020-10-30 17:12:31 |
| R24.htm | 102706 | 2020-10-30 17:12:31 |
| R25.htm | 16232 | 2020-10-30 17:12:31 |
| R26.htm | 5230 | 2020-10-30 17:12:31 |
| R27.htm | 30134 | 2020-10-30 17:12:31 |
| R28.htm | 63008 | 2020-10-30 17:12:31 |
| R29.htm | 45492 | 2020-10-30 17:12:31 |
| R3.htm | 24257 | 2020-10-30 17:12:31 |
| R30.htm | 11060 | 2020-10-30 17:12:31 |
| R31.htm | 147475 | 2020-10-30 17:12:31 |
| R32.htm | 34586 | 2020-10-30 17:12:31 |
| R33.htm | 11974 | 2020-10-30 17:12:31 |
| R34.htm | 20345 | 2020-10-30 17:12:31 |
| R35.htm | 59834 | 2020-10-30 17:12:31 |
| R36.htm | 77836 | 2020-10-30 17:12:31 |
| R37.htm | 13161 | 2020-10-30 17:12:31 |
| R38.htm | 287213 | 2020-10-30 17:12:31 |
| R39.htm | 51038 | 2020-10-30 17:12:31 |
| R4.htm | 125241 | 2020-10-30 17:12:31 |
| R40.htm | 8546 | 2020-10-30 17:12:31 |
| R41.htm | 94778 | 2020-10-30 17:12:31 |
| R42.htm | 35241 | 2020-10-30 17:12:31 |
| R43.htm | 7850 | 2020-10-30 17:12:31 |
| R44.htm | 7015 | 2020-10-30 17:12:31 |
| R45.htm | 50361 | 2020-10-30 17:12:31 |
| R46.htm | 38846 | 2020-10-30 17:12:31 |
| R47.htm | 16788 | 2020-10-30 17:12:31 |
| R48.htm | 49414 | 2020-10-30 17:12:31 |
| R49.htm | 14468 | 2020-10-30 17:12:31 |
| R5.htm | 40109 | 2020-10-30 17:12:31 |
| R50.htm | 17616 | 2020-10-30 17:12:31 |
| R51.htm | 9495 | 2020-10-30 17:12:31 |
| R52.htm | 31461 | 2020-10-30 17:12:31 |
| R53.htm | 34776 | 2020-10-30 17:12:31 |
| R54.htm | 13323 | 2020-10-30 17:12:31 |
| R55.htm | 11321 | 2020-10-30 17:12:31 |
| R56.htm | 14358 | 2020-10-30 17:12:31 |
| R57.htm | 6901 | 2020-10-30 17:12:31 |
| R58.htm | 67835 | 2020-10-30 17:12:31 |
| R59.htm | 27927 | 2020-10-30 17:12:31 |
| R6.htm | 173202 | 2020-10-30 17:12:31 |
| R60.htm | 19663 | 2020-10-30 17:12:31 |
| R61.htm | 17532 | 2020-10-30 17:12:31 |
| R62.htm | 16882 | 2020-10-30 17:12:31 |
| R63.htm | 34730 | 2020-10-30 17:12:31 |
| R64.htm | 88023 | 2020-10-30 17:12:31 |
| R65.htm | 43271 | 2020-10-30 17:12:31 |
| R66.htm | 17875 | 2020-10-30 17:12:31 |
| R67.htm | 106918 | 2020-10-30 17:12:31 |
| R68.htm | 16846 | 2020-10-30 17:12:31 |
| R69.htm | 17337 | 2020-10-30 17:12:31 |
| R7.htm | 15443 | 2020-10-30 17:12:31 |
| R70.htm | 94976 | 2020-10-30 17:12:31 |
| R71.htm | 38092 | 2020-10-30 17:12:31 |
| R72.htm | 54837 | 2020-10-30 17:12:31 |
| R73.htm | 16446 | 2020-10-30 17:12:31 |
| R74.htm | 24631 | 2020-10-30 17:12:31 |
| R75.htm | 12828 | 2020-10-30 17:12:31 |
| R76.htm | 19662 | 2020-10-30 17:12:31 |
| R77.htm | 75792 | 2020-10-30 17:12:31 |
| R78.htm | 66307 | 2020-10-30 17:12:31 |
| R79.htm | 32978 | 2020-10-30 17:12:31 |
| R8.htm | 182504 | 2020-10-30 17:12:31 |
| R80.htm | 15201 | 2020-10-30 17:12:31 |
| R81.htm | 16186 | 2020-10-30 17:12:31 |
| R9.htm | 11707 | 2020-10-30 17:12:31 |
| report.css | 2767 | 2020-10-30 17:12:31 |
| Show.js | 1085 | 2020-10-30 17:12:31 |