Quarterly report pursuant to Section 13 or 15(d)

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

v3.20.2
Workers' Compensation Claims - Summarizes Aggregate Workers' Compensation Reserve Activity (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Workers Compensation Reserve [Abstract]        
Workers' compensation claims liabilities, Beginning balance $ 445,310 $ 422,872 $ 438,986 $ 413,397
Add: claims expense accrual        
Current period 32,729 41,145 71,221 81,530
Prior periods (1,373) (2,952) (2,186) (4,652)
Total expense accrual 31,356 38,193 69,035 76,878
Less: claim payments related to        
Current period 4,527 4,145 6,077 5,604
Prior periods 135,853 26,088 165,530 53,804
Total paid 140,380 30,233 171,607 59,408
Change in claims incurred in excess of retention limits 218 (96) 90 (131)
Workers' compensation claims liabilities, Ending balance 336,504 430,736 336,504 430,736
Incurred but not reported (IBNR) $ 206,521 $ 273,114 $ 206,521 $ 273,114
Ratio of IBNR to workers' compensation claims liabilities 61.00% 63.00% 61.00% 63.00%