Self-Insurance Accruals (Tables)

12 Months Ended

Dec. 31, 2016

Self-Insurance Accruals [Abstract]

Schedule of self-insurance accruals [Table Text Block]

Components of our self-insurance accruals for workers’ compensation, vehicle liability and general liability follow:

	December 31,
	2016		2015
Workers' compensation	$	38,811	$	35,304
Present value discount	2,236		1,937
	36,575		33,367
Vehicle liability	4,763		5,880
General liability	21,500		21,092
Total	62,838		60,339
Less current portion	23,092		22,553
Noncurrent portion	$	39,746	$	37,786

Schedule of changes in self-insurance accruals [Table Text Block]

The changes in our self-insurance accruals and the discount rate used for the workers’ compensation accrual are summarized in the table below.

	December 31,
	2016			2015
Balance, beginning of year	$	60,339		$	58,893
Provision for claims	33,404			33,499
Payment of claims	30,905			32,053
Balance, end of year	$	62,838		$	60,339
Workers' compensation discount rate	2.20		%	2.20		%