Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.3
Workers' Compensation Claims - Summarizes Aggregate Workers' Compensation Reserve Activity (Detail) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Workers Compensation Reserve [Abstract]        
Workers' compensation claims liabilities, Beginning balance $ 430,736 $ 390,814 $ 413,397 $ 363,517
Add: claims expense accrual        
Current period 37,404 37,784 118,934 116,803
Prior periods (5,593) (2,327) (10,245) (2,333)
Total expense accrual 31,811 35,457 108,689 114,470
Less: claim payments related to        
Current period 8,609 7,502 14,213 13,783
Prior periods 23,815 19,905 77,619 65,296
Total paid 32,424 27,407 91,832 79,079
Change in claims incurred in excess of retention limits (77) (26) (208) (70)
Workers' compensation claims liabilities, Ending balance 430,046 398,838 430,046 398,838
Incurred but not reported (IBNR) $ 274,344 $ 246,174 $ 274,344 $ 246,174
Ratio of IBNR to workers' compensation claims liabilities 64.00% 62.00% 64.00% 62.00%