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

12 Months Ended

Dec. 31, 2013

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, 2013 and December 31, 2012, were as follows:

			Fair Value Measurements at December 31, 2013 Using:
	Total Carrying Value at		Quoted prices in active markets		Significant other observable inputs		Significant unobservable inputs
Description	December 31, 2013		(Level 1)		(Level 2)		(Level 3)
Assets:
Assets invested for self-insurance, classified as other assets, noncurrent	$	12,716	$	12,716	$	—	$	—
Defined benefit pension plan assets	25,754		24,028		1,726		—
Liabilities:
Deferred compensation	$	1,144	$	—	$	1,144	$	—

			Fair Value Measurements at December 31, 2012 Using:
	Total Carrying Value at		Quoted prices in active markets		Significant other observable inputs		Significant unobservable inputs
Description	December 31, 2012		(Level 1)		(Level 2)		(Level 3)
Assets:
Assets invested for self-insurance, classified as other assets, noncurrent	$	10,758	$	10,758	$	—	$	—
Fuel derivatives, classified as other current assets	38		—		38		—
Defined benefit pension plan assets	22,957		20,463		2,494		—
Liabilities:
Fuel derivatives, classified as accrued expenses	$	24	$	—	$	24	$	—
Deferred compensation	873		—		873		—

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, 2013				December 31, 2012
	Carrying Value		Fair Value		Carrying Value		Fair Value
Revolving credit facility, noncurrent	$	20,000	$	20,000	$	24,200	$	24,200
Senior unsecured notes	30,000		28,219		30,000		29,762
Term loans, noncurrent	34		34		587		587
Total	$	50,034	$	48,253	$	54,787	$	54,549

Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]

The following tables sets forth quantitative information related to our derivatives instruments and where these amounts are recorded in our consolidated financial statements.

	As of December 31,
	2013		2012
Economic Hedges - Derivatives Not Designated as Hedging Instruments
Fuel Derivatives:
Asset fair value of fuel derivatives, classified as other current assets	$	—	$	38
Liability fair value of fuel derivatives, classified as accrued expenses	$	—	$	24
Liability fair value of fuel derivatives, classified as other noncurrent liabilities	$	—	$	—
Longest remaining term, in months	—		12
Notional hedged volume, in thousands of gallons	—		1,250

	Year Ended December 31,
	2013		2012
Cash Flow Hedges - Derivatives Designated as Hedging Instruments
Interest Rate Swaps:
Hedge gains, recognized in other comprehensive income	$	—	$	123
Economic Hedges - Derivatives Not Designated as Hedging Instruments
Fuel Derivatives:
Change in fair value, recognized in results of operations, as a reduction in costs and expenses, operating	$	139	$	650