Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income tax expense consisted of the following (in thousands):

The effective income tax rate differs from the federal corporate tax rate of 21% in 2021, 2020, and 2019 as follows (in thousands):


	Years Ended December 31,
	2021		2020		2019
Tax at statutory rate	$	72,663	$	47,186	$	46,600
State income taxes, net of federal tax benefits	11,599		8,580		8,575
Other, net (1)	275		(150)		(213)
Total income tax expense	$	84,537	$	55,616	$	54,962

(1) Prior year amounts within the table have been reclassified to conform to current year presentation.

At December 31, deferred income tax assets and liabilities consisted of the following (in thousands):


	December 31,
	2021		2020
Deferred income tax assets:
Insurance and claims accruals	$	55,233	$	54,913
Compensation-related accruals	12,203		16,054
Allowance for uncollectible accounts	3,958		4,070
Operating lease liabilities (1)	7,033		2,530
Other (1)	1,644		2,844
Gross deferred income tax assets	80,071		80,411
Deferred income tax liabilities:
Property and equipment	305,002		308,145
Investments in equity securities	10,985		—
Prepaid expenses	7,269		6,333
Operating lease right-of-use assets (1)	6,955		2,485
Investment in partnership	17,076		—
Other (1)	1,283		1,318
Gross deferred income tax liabilities	348,570		318,281
Net deferred income tax liability	$	268,499	$	237,870

The reconciliations of beginning and ending gross balances of unrecognized tax benefits for 2021 and 2020 are shown below (in thousands).


	December 31,
	2021		2020
Unrecognized tax benefits, beginning balance	$	2,363	$	2,541
Gross increases – tax positions in prior period	65		92
Gross increases – current period tax positions	320		220
Settlements	(323)		(490)
Unrecognized tax benefits, ending balance	$	2,425	$	2,363