Workers' Compensation Claims (Tables)

12 Months Ended

Dec. 31, 2016

Text Block [Abstract]

Summarizes Aggregate Workers' Compensation Reserve Activity

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

	Year Ended December 31,
	2016			2015			2014
Balance at January 1,
Workers' compensation claims liabilities	$	255,675		$	225,278		$	121,056
Add: claims expense accrual
Current year		137,852			122,740			104,314
Prior years		(301	)		(13,683	)		66,719
		137,551			109,057			171,033
Less: claims payments related to
Current year		20,180			17,517			15,243
Prior years		69,626			61,143			51,568
		89,806			78,660			66,811
Add: claims incurred in excess of retention limits		9,117			—			—
Balance at December 31,
Workers' compensation claims liabilities	$	312,537		$	255,675		$	225,278
Incurred but not reported (IBNR)	$	158,169		$	127,792		$	113,984