Fair Value Measurements and Financial Instruments Fair Value Measurements and Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2016

Fair value, assets and liabilities measured on recurring and nonrecurring basis [Line Items]

Fair value, assets measured on recurring basis [Table Text Block]

Our assets and liabilities measured at fair value on a recurring basis at December 31, 2016 and December 31, 2015, were as follows:

			Fair Value Measurements at December 31, 2016 Using:
	Total Carrying Value at		Quoted prices in active markets		Significant other observable inputs		Significant unobservable inputs
Description	December 31, 2016		(Level 1)		(Level 2)		(Level 3)
Assets:
Assets invested for self-insurance, classified as other assets, noncurrent	$	15,492	$	15,492	$	—	$	—
Defined benefit pension plan assets	11,509		8,627		2,882		—
Liabilities:
Deferred compensation	$	1,837	$	—	$	1,837	$	—

			Fair Value Measurements at December 31, 2015 Using:
	Total Carrying Value at		Quoted prices in active markets		Significant other observable inputs		Significant unobservable inputs
Description	December 31, 2015		(Level 1)		(Level 2)		(Level 3)
Assets:
Assets invested for self-insurance, classified as other assets, noncurrent	$	17,167	$	17,167	$	—	$	—
Defined benefit pension plan assets	15,216		12,422		2,794		—
Liabilities:
Deferred compensation	$	1,574	$	—	$	1,574	$	—

Fair value, by balance sheet grouping [Table Text Block]

Financial instruments classified as noncurrent liabilities and their carrying values and fair values were as follows:

	December 31, 2016				December 31, 2015
	Carrying Value		Fair Value		Carrying Value		Fair Value
Revolving credit facility, noncurrent	$	67,000	$	67,000	$	54,500	$	54,500
Senior unsecured notes	18,000		18,509		24,000		24,837
Term loans, noncurrent	7,623		9,854		6,604		7,008
Total	$	92,623	$	95,363	$	85,104	$	86,345