Nature of operations and summary of significant accounting policies (Details-Accrued hauler expenses) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2021 |
Dec. 31, 2020 |
|
| Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items] | ||
| Accrued expenses beginning | $ 37,429 | $ 41,339 |
| Changes in estimate related to prior period | 156 | 1,804 |
| Estimated accrual related to current period | 56,984 | 43,357 |
| Accrued expenses ending | 49,607 | 37,429 |
| Accrued Liabilities [Member] | ||
| Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items] | ||
| Invoiced by vendors in the current period | (37,726) | (43,288) |
| Changes in estimate related to prior period | 297 | 1,949 |
| Estimated accrual related to current period | $ 49,607 | $ 37,429 |