Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0001193125-21-022513-index-headers.html | 2021-01-29 15:32:01 | |
| 0001193125-21-022513-index.html | 2021-01-29 15:32:01 | |
| 0001193125-21-022513.txt | 2021-01-29 15:32:01 | |
 0001193125-21-022513-xbrl.zip | 35311 | 2021-01-29 15:32:01 |
| btu-20210126.xsd | 3081 | 2021-01-29 15:32:01 |
| btu-20210126_lab.xml | 17373 | 2021-01-29 15:32:01 |
| btu-20210126_pre.xml | 10961 | 2021-01-29 15:32:01 |
| d215085d8k.htm | 62518 | 2021-01-29 15:32:01 |
| d215085d8k_htm.xml | 3276 | 2021-01-29 15:32:01 |
| d215085dex43.htm | 30538 | 2021-01-29 15:32:01 |
| d215085dex44.htm | 36500 | 2021-01-29 15:32:01 |
| d215085dex991.htm | 11650 | 2021-01-29 15:32:01 |
| d215085dex992.htm | 12930 | 2021-01-29 15:32:01 |
| FilingSummary.xml | 1832 | 2021-01-29 15:32:01 |
| Financial_Report.xlsx | 5457 | 2021-01-29 15:32:01 |
 g215085logo_01.jpg | 3906 | 2021-01-29 15:32:01 |
| MetaLinks.json | 18388 | 2021-01-29 15:32:01 |
| R1.htm | 38621 | 2021-01-29 15:32:01 |
| report.css | 2767 | 2021-01-29 15:32:01 |
| Show.js | 1085 | 2021-01-29 15:32:01 |