Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0001564590-18-012675-index-headers.html | 2018-05-10 06:44:15 | |
| 0001564590-18-012675-index.html | 2018-05-10 06:44:15 | |
| 0001564590-18-012675.txt | 2018-05-10 06:44:15 | |
 0001564590-18-012675-xbrl.zip | 278338 | 2018-05-10 06:44:15 |
| extr-10q_20180331.htm | 3603394 | 2018-05-10 06:44:15 |
| extr-20180331.xml | 5151938 | 2018-05-10 06:44:15 |
| extr-20180331.xsd | 83749 | 2018-05-10 06:44:15 |
| extr-20180331_cal.xml | 82017 | 2018-05-10 06:44:15 |
| extr-20180331_def.xml | 334704 | 2018-05-10 06:44:15 |
| extr-20180331_lab.xml | 639016 | 2018-05-10 06:44:15 |
| extr-20180331_pre.xml | 547023 | 2018-05-10 06:44:15 |
| extr-ex311_7.htm | 19069 | 2018-05-10 06:44:15 |
| extr-ex312_9.htm | 19319 | 2018-05-10 06:44:15 |
| extr-ex321_11.htm | 7286 | 2018-05-10 06:44:15 |
| extr-ex322_8.htm | 7270 | 2018-05-10 06:44:15 |
| FilingSummary.xml | 54880 | 2018-05-10 06:44:15 |
| Financial_Report.xlsx | 114708 | 2018-05-10 06:44:15 |
| R1.htm | 21944 | 2018-05-10 06:44:15 |
| R10.htm | 415099 | 2018-05-10 06:44:15 |
| R11.htm | 415548 | 2018-05-10 06:44:15 |
| R12.htm | 145671 | 2018-05-10 06:44:15 |
| R13.htm | 194709 | 2018-05-10 06:44:15 |
| R14.htm | 57912 | 2018-05-10 06:44:15 |
| R15.htm | 25977 | 2018-05-10 06:44:15 |
| R16.htm | 19941 | 2018-05-10 06:44:15 |
| R17.htm | 79871 | 2018-05-10 06:44:15 |
| R18.htm | 7862 | 2018-05-10 06:44:15 |
| R19.htm | 179560 | 2018-05-10 06:44:15 |
| R2.htm | 81049 | 2018-05-10 06:44:15 |
| R20.htm | 9109 | 2018-05-10 06:44:15 |
| R21.htm | 627683 | 2018-05-10 06:44:15 |
| R22.htm | 281952 | 2018-05-10 06:44:15 |
| R23.htm | 156842 | 2018-05-10 06:44:15 |
| R24.htm | 405711 | 2018-05-10 06:44:15 |
| R25.htm | 418012 | 2018-05-10 06:44:15 |
| R26.htm | 136738 | 2018-05-10 06:44:15 |
| R27.htm | 193234 | 2018-05-10 06:44:15 |
| R28.htm | 52788 | 2018-05-10 06:44:15 |
| R29.htm | 81228 | 2018-05-10 06:44:15 |
| R3.htm | 20727 | 2018-05-10 06:44:15 |
| R30.htm | 179003 | 2018-05-10 06:44:15 |
| R31.htm | 82408 | 2018-05-10 06:44:15 |
| R32.htm | 16508 | 2018-05-10 06:44:15 |
| R33.htm | 72734 | 2018-05-10 06:44:15 |
| R34.htm | 30763 | 2018-05-10 06:44:15 |
| R35.htm | 34179 | 2018-05-10 06:44:15 |
| R36.htm | 15011 | 2018-05-10 06:44:15 |
| R37.htm | 36680 | 2018-05-10 06:44:15 |
| R38.htm | 33513 | 2018-05-10 06:44:15 |
| R39.htm | 8861 | 2018-05-10 06:44:15 |
| R4.htm | 70056 | 2018-05-10 06:44:15 |
| R40.htm | 51180 | 2018-05-10 06:44:15 |
| R41.htm | 63877 | 2018-05-10 06:44:15 |
| R42.htm | 42909 | 2018-05-10 06:44:15 |
| R43.htm | 16250 | 2018-05-10 06:44:15 |
| R44.htm | 115410 | 2018-05-10 06:44:15 |
| R45.htm | 9744 | 2018-05-10 06:44:15 |
| R46.htm | 19045 | 2018-05-10 06:44:15 |
| R47.htm | 39859 | 2018-05-10 06:44:15 |
| R48.htm | 10615 | 2018-05-10 06:44:15 |
| R49.htm | 7370 | 2018-05-10 06:44:15 |
| R5.htm | 18835 | 2018-05-10 06:44:15 |
| R50.htm | 17599 | 2018-05-10 06:44:15 |
| R51.htm | 12720 | 2018-05-10 06:44:15 |
| R52.htm | 9524 | 2018-05-10 06:44:15 |
| R53.htm | 12849 | 2018-05-10 06:44:15 |
| R54.htm | 29158 | 2018-05-10 06:44:15 |
| R55.htm | 52795 | 2018-05-10 06:44:15 |
| R56.htm | 14410 | 2018-05-10 06:44:15 |
| R57.htm | 10987 | 2018-05-10 06:44:15 |
| R58.htm | 17486 | 2018-05-10 06:44:15 |
| R59.htm | 28821 | 2018-05-10 06:44:15 |
| R6.htm | 85366 | 2018-05-10 06:44:15 |
| R60.htm | 46688 | 2018-05-10 06:44:15 |
| R61.htm | 67579 | 2018-05-10 06:44:15 |
| R62.htm | 20118 | 2018-05-10 06:44:15 |
| R63.htm | 27012 | 2018-05-10 06:44:15 |
| R64.htm | 23100 | 2018-05-10 06:44:15 |
| R65.htm | 17173 | 2018-05-10 06:44:15 |
| R66.htm | 33889 | 2018-05-10 06:44:15 |
| R67.htm | 10275 | 2018-05-10 06:44:15 |
| R68.htm | 13602 | 2018-05-10 06:44:15 |
| R69.htm | 18129 | 2018-05-10 06:44:15 |
| R7.htm | 12023 | 2018-05-10 06:44:15 |
| R70.htm | 6289 | 2018-05-10 06:44:15 |
| R71.htm | 33772 | 2018-05-10 06:44:15 |
| R72.htm | 10734 | 2018-05-10 06:44:15 |
| R73.htm | 47364 | 2018-05-10 06:44:15 |
| R8.htm | 294597 | 2018-05-10 06:44:15 |
| R9.htm | 171678 | 2018-05-10 06:44:15 |
| report.css | 2767 | 2018-05-10 06:44:15 |
| Show.js | 1410 | 2018-05-10 06:44:15 |