Note 7 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

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

	Years ended December 31,
	2021		2020			2019
Current:
Federal	$	142,542	$	138,952		$	87,977
State and local		43,004		28,094			20,981
		185,546		167,046			108,958
Deferred:
Federal		43,900		(2,392	)		51,229
State and local		9,520		(4,664	)		4,388
		53,420		(7,056	)		55,617
Total tax expense/(benefit)	$	238,966	$	159,990		$	164,575

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Years ended December 31,
	2021			2020			2019
Income tax at federal statutory rate	$	209,952		$	139,865		$	142,988
State tax, net of federal effect		37,223			20,071			19,293
Benefit of stock compensation		(7,583	)		(3,503	)		(1,238	)
199/R&D credit		(1,524	)		-			(200	)
Nondeductible meals and entertainment		130			1,344			1,688
Change in effective state tax rate, net of federal benefit		(724	)		98			1,562
Other, net		1,492			2,115			482
Total tax expense	$	238,966		$	159,990		$	164,575

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

	December 31,
	2021			2020
Deferred tax assets:
Insurance accruals	$	27,487		$	24,304
Allowance for doubtful accounts		8,886			9,270
Compensation accrual		22,061			10,809
CARES Act payroll tax deferral		9,955			19,931
Deferred compensation accrual		28,937			25,702
Federal benefit of state uncertain tax positions		12,870			10,312
Lease liabilities		43,850			32,625
State NOL carry-forward		7,303			8,460
Other		5,549			4,237
Total gross deferred tax assets		166,898			145,650
Valuation allowance		(7,303	)		(8,460	)
Total deferred tax assets, net of valuation allowance		159,595			137,190
Deferred tax liabilities:
Plant and equipment, principally due to differences in depreciation		816,744			748,883
Prepaid permits and insurance, principally due to expensing for income tax purposes		44,132			42,126
Lease right-of-use assets		44,161			32,952
Other		-			5,251
Total gross deferred tax liabilities		905,037			829,212
Net deferred tax liability	$	745,442		$	692,022

Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table Text Block]

	December 31,
	2021			2020			2019
Beginning balance	$	66.1		$	50.6		$	52.2
Additions based on tax positions related to the current year		14.9			9.8			11.0
Additions/(reductions) based on tax positions taken in prior years		4.8			13.9			(6.5	)
Reductions due to settlements		(0.9	)		(1.0	)		-
Reductions due to lapse of applicable statute of limitations		(6.4	)		(7.2	)		(6.1	)
Ending balance	$	78.5		$	66.1		$	50.6