Workers' Compensation Claims (Tables)

12 Months Ended

Dec. 31, 2018

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Summarizes Aggregate Workers' Compensation Reserve Activity

The following table summarizes the aggregate workers' compensation reserve activity (in thousands):

	Years Ended December 31,
	2018			2017			2016
Beginning balance
Workers' compensation claims liabilities	$	363,517		$	312,537		$	255,675
Add: claims expense accrual
Current period		162,525			154,091			137,852
Prior periods		(3,846	)		5,159			(301	)
		158,679			159,250			137,551
Less: claim payments related to
Current period		23,444			19,537			20,180
Prior periods		85,603			82,573			69,626
		109,047			102,110			89,806
Add: change in claims incurred in excess of       retention limits		248			(6,160	)		9,117
Ending balance
Workers' compensation claims liabilities	$	413,397		$	363,517		$	312,537
Incurred but not reported (IBNR)	$	260,529		$	202,227		$	158,169
Ratio of IBNR to workers' compensation claims    liabilities		63	%		56	%		51	%