Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

Deferred tax assets and liabilities as of December 31 are as follows:

	2020		2019
Deferred income tax assets:	(in thousands)
Allowance for doubtful accounts	$	258	$	262
Accrued expenses	6,353		3,892
Stock-based compensation	126		178
Insurance accruals	14,283		15,054
State net operating loss carryforward	—		2,618
Federal net operating loss carryover and credits	—		8,793
Indirect tax benefits of unrecognized tax benefits	1,037		1,052
Other	221		3
Total gross deferred tax assets	22,278		31,852
Less valuation allowance	—		—
Net deferred tax assets	22,278		31,852
Deferred income tax liabilities:
Property and equipment	(98,355)		(101,843)
Goodwill and amortizable intangibles	(18,959)		(15,939)
Prepaid expenses	(804)		(1,762)
	(118,118)		(119,544)
Net deferred tax liability	$	(95,840)	$	(87,692)

The deferred tax amounts above have been classified in the accompanying consolidated balance sheets at December 31, 2020 and 2019 as follows:

	2020		2019
	(in thousands)
Noncurrent assets, net	$	8,164	$	6,006
Long-term liabilities, net	(104,004)		(93,698)
	$	(95,840)	$	(87,692)

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

Income tax expense consists of the following:

	2020		2019		2018
	(in thousands)
Current income taxes:
Federal	$	10,835	$	14,122	$	11,985
State	4,472		5,698		4,498
	15,307		19,820		16,483
Deferred income taxes:
Federal	736		5,595		5,537
State	7,412		(1,204)		(2,780)
	8,148		4,391		2,757
Total	$	23,455	$	24,211	$	19,240

The income tax provision differs from the amount determined by applying the U.S. federal tax rate as follows:

	2020		2019		2018
	(in thousands)
Federal tax at statutory rate (21%, 21%, 21% respectively)	$	19,795	$	20,406	$	19,302
State taxes, net of federal benefit	5,678		3,561		2,200
Permanent differences to return	446		540		408
Return to provision adjustment	(2,615)		(392)		(1,327)
Uncertain income tax penalties and interest, net	(73)		289		(1,067)
Other	224		(193)		(276)
	$	23,455	$	24,211	$	19,240

Reconciliation of Unrecognized Tax Benefits [Table Text Block]

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:

	2020		2019
	(in thousands)
Balance at January 1,	$	5,010	$	4,585
Additions based on tax positions related to current year	767		1,138
Additions for tax positions of prior years	—		124
Reductions for tax positions of prior years	(216)		—
Reductions due to lapse of applicable statute of limitations	(428)		(701)
Settlements	(196)		(136)
Balance at December 31,	$	4,937	$	5,010