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Accounting Policies (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Jun. 30, 2022 | Jun. 30, 2021 | Jun. 30, 2022 | Jun. 30, 2021 | Dec. 31, 2021 | Dec. 31, 2020 | Oct. 01, 2019
Health Insurance Costs [Abstract] |  |  |  |  |  |  |
Percentage of our health insurance coverage provided by United | 87.00% |  | 87.00% |  |  |  |
Number of days in advance of the beginning of a reporting quarter United establishes cash funding rates |  |  | 90 days |  |  |  |
Required accumulated cash surplus | $ 9,000 |  | $ 9,000 |  | $ 9,000 |  |
Required deposit equal to approximately one day of claims funding activity | 6,500 |  | 6,500 |  |  |  |
Amount which plan costs were less than the net premiums paid and owed | 41,800 |  | 41,800 |  |  |  |
Prepaid health insurance, current | 32,800 |  | 32,800 |  |  |  |
Premiums owed to United | 55,900 |  | 55,900 |  |  |  |
Benefits costs incurred (reduced) related to run-off | (10,200) | $ (5,700) | (10,200) | $ (5,700) |  |  |
Workers' Compensation Costs [Abstract] |  |  |  |  |  |  |
Company's maximum economic burden for the first layer of claims per occurrence | 1,000 |  | 1,000 |  |  |  | $ 1,500
Company's maximum aggregate economic burden for claims in excess of 1 million per policy year | 6,000 |  | 6,000 |  |  |  | $ 6,000
Decrease Increase in accrued workers' compensation costs for changes in estimated losses |  |  | $ 26,800 | $ 23,000 |  |  |
U.S. Treasury rates that correspond with the weighted average estimated claim payout period (in hundredths) |  |  | 2.00% | 0.50% |  |  |
Incurred but not paid workers compensation liabilities [Abstract] |  |  |  |  |  |  |
Liability for Unpaid Claims and Claims Adjustment Expense, Adjustments |  |  |  |  | 239,623 | $ 240,761 |
Workers' Compensation Expense |  |  | $ 18,780 | $ 20,559 |  |  |
Present value discount, net of accretion |  |  | (3,501) | 407 |  |  |
Paid claims |  |  | (27,899) | (22,904) |  |  |
WorkersCompensationLiabilityNetOfAdminFeesCurrent | 53,317 | 46,120 | 53,317 | 46,120 |  |  |
Long-term portion of accrued claims | 173,686 | 192,703 | 173,686 | 192,703 | 192,694 |  |
Ending balance | 227,003 | 238,823 | 227,003 | 238,823 |  |  |
Workers compensation administrative fees accrued | 4,800 |  | 4,800 |  |  |  |
Undiscounted accrued workers' compensation costs |  |  | $ 243,900 | 254,800 |  |  |
Time period incurred claims expected to be paid recorded as restricted cash |  |  | 1 year |  |  |  |
Time period incurred claims expected to be paid, included in deposits, a long-term asset |  |  | Greater than 1 year |  |  |  |
Restricted cash | 53,329 | 46,128 | $ 53,329 | 46,128 | 46,929 | 45,522 |
Deposits workers compensation | 166,077 | 203,612 | $ 166,077 | 203,612 | 185,027 | $ 186,331 |
Time period estimate of incurred claim costs to be paid included in short-term liabilities |  |  | 1 year |  |  |  |
Time period incurred claims expected to be paid, included in long-term liabilities |  |  | Greater than 1 year |  |  |  |
Revenue from Contract with Customer [Abstract] |  |  |  |  |  |  |
Unbilled | 674,400 |  | $ 674,400 |  | $ 490,500 |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Revenue from Contract with Customer, Excluding Assessed Tax | 1,432,107 | 1,185,371 | 3,009,944 | 2,472,206 |  |  |
ReturnOfExcessClaimFunds |  |  | 30,200 |  |  |  |
Northeast [Member] |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Revenue from Contract with Customer, Excluding Assessed Tax | 388,680 | 329,016 | 838,602 | 702,645 |  |  |
Southeast [Member] |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Revenue from Contract with Customer, Excluding Assessed Tax | 192,782 | 150,810 | 394,985 | 307,070 |  |  |
Central [Member] |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Revenue from Contract with Customer, Excluding Assessed Tax | 252,039 | 206,084 | 523,350 | 431,784 |  |  |
Southwest [Member] |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Revenue from Contract with Customer, Excluding Assessed Tax | 279,936 | 238,368 | 588,774 | 495,348 |  |  |
West [Member] |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Revenue from Contract with Customer, Excluding Assessed Tax | 304,380 | 247,184 | 635,152 | 508,538 |  |  |
Other Revenues [Member] |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Revenue from Contract with Customer, Excluding Assessed Tax | $ 14,290 | $ 13,909 | $ 29,081 | $ 26,821 |  |  |

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