Quarterly report pursuant to Section 13 or 15(d)

Workers' Compensation Claims - Summarizes Aggregate Workers' Compensation Reserve Activity (Detail)

v3.21.1
Workers' Compensation Claims - Summarizes Aggregate Workers' Compensation Reserve Activity (Detail) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Workers Compensation Reserve [Abstract]    
Workers' compensation claims liabilities, Beginning balance $ 357,746 $ 438,986
Add: claims expense accrual    
Current period 33,270 38,492
Prior periods (1,180) (813)
Total expense accrual 32,090 37,679
Less: claim payments related to    
Current period 1,050 1,550
Prior periods 25,767 29,677
Total paid 26,817 31,227
Change in claims incurred in excess of retention limits (356) (128)
Workers' compensation claims liabilities, Ending balance 362,663 445,310
Incurred but not reported (IBNR) $ 212,297 $ 282,497
Ratio of IBNR to workers' compensation claims liabilities 59.00% 63.00%