Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2019

Fair Value Disclosures [Abstract]

Schedule of Fair Values of Financial Instruments and Nonfinancial Assets and Liabilities Measured at the Reporting Date

The fair values of these financial instruments are summarized as follows:

			Fair Value Measurements at Reporting Date Using
Description	At June 30, 2019		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Fuel hedge contracts	$	678	$	—	$	678	$	—

			Fair Value Measurements at Reporting Date Using
Description	At December 31, 2018		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Fuel hedge contracts	$	4,710	$	—	$	4,710	$	—

Schedule of Fair Value of Fuel Hedge Contracts Balance Sheet Location

The fair value of the fuel hedge contracts outstanding as of June 30, 2019 and December 31, 2018 is as follows:

		Fair Value at
		June 30,		December 31,
	Balance Sheet Location	2019		2018
Liability derivatives:
Derivatives designated as hedging instruments
Fuel hedge contracts	Accrued expenses	$	678	$	4,710

Changes in Components of Accumulated Other Comprehensive Income (Loss)

Changes in the components of the accumulated balances of other comprehensive income (loss) are as follows:

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2019			2018			2019		2018
Cumulative translation adjustments—net of tax	$	—		$	(57	)	$	—	$	1,304
Derivatives:
Reclassification of derivative (gains) losses to earnings—net of tax		295			(1,037	)		1,186		(1,769	)
Change in fair value of derivatives—net of tax		(58	)		910			1,791		908
Net change in cash flow derivative hedges—net of tax		237			(127	)		2,977		(861	)
Total other comprehensive income (loss)	$	237		$	(184	)	$	2,977	$	443

Adjustments Reclassified from Accumulated Balances Other Comprehensive Income (Loss) to Earnings

Adjustments reclassified from accumulated balances of other comprehensive income (loss) to earnings are as follows:

		Three Months Ended					Six Months Ended
		June 30,					June 30,
	Statement of Operations Location	2019			2018		2019		2018
Derivatives:
Fuelhedge contracts	Costs of contract revenues	$	399	$	(1,404	)	$	1,606	$	(2,396	)
	Income tax (provision) benefit		104		(367	)		420		(627	)
		$	295	$	(1,037	)	$	1,186	$	(1,769	)

Adjustments reclassified from accumulated balances of other comprehensive income (loss) to earnings are as follows:

		Six Months Ended
	Statement of Operations Location	June 30, 2018
Cumulative translation adjustment:	Other expense	$	(2,015	)
	Income tax benefit		527
		$	(1,487	)