9. Income Taxes

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Deferred tax liabilities (assets) are comprised of the following at December 31 (in thousands):

	2016			2015
Depreciation	$	117,625		$	103,471
Other		1,414			3,482

Gross deferred tax liabilities		119,039			106,953
Allowance for doubtful accounts		(1,225	)		(1,350	)
Equity-based compensation		(4,538	)		(3,961	)
Employee benefits		(6,115	)		(4,847	)
Claims and insurance		(23,241	)		(20,942	)
Other		(3,721	)		(8,436	)

Gross deferred tax assets		(38,840	)		(39,536	)

Net deferred tax liability	$	80,199		$	67,417

The Company has determined that a valuation allowance related to deferred tax assets was not necessary at December 31, 2016 or 2015 since it is more likely than not the deferred tax assets will be realized from future reversals of temporary differences or future taxable income.

The income tax provision (benefit) for continuing operations consists of the following (in thousands):

	2016		2015			2014
Current:
U.S. federal	$	12,127	$	20,768		$	18,085
State		1,988		1,759			1,690

Total current income tax provision		14,115		22,527			19,775

Deferred:
U.S. federal		12,599		8,570			9,547
State		181		(150	)		(85	)

Total deferred income tax provision		12,780		8,420			9,462

Total income tax provision	$	26,895	$	30,947		$	29,237

A reconciliation between income taxes at the federal statutory rate (35 percent) and the effective income tax provision is as follows (in thousands):

	2016			2015			2014
Provision at federal statutory rate	$	26,222		$	30,087		$	28,430
State income taxes, net		2,418			2,229			2,426
Nondeductible business expenses		462			696			589
Tax credits		(1,278	)		(1,532	)		(1,434	)
Other, net		(929	)		(533	)		(774	)

Total provision	$	26,895		$	30,947		$	29,237

The Company and its subsidiaries file income tax returns in the U.S. federal jurisdiction and various state jurisdictions. For the U.S. federal jurisdiction, tax years 2014-2016 remain open to examination. The expiration of the statute of limitations related to the various state income tax returns that the Company files varies by state. In general, tax years 2007-2016 remain open to examination by the various state and local jurisdictions. However, a state could challenge certain tax positions back to the 2003 tax year.

A reconciliation of the beginning and ending total amounts of gross unrecognized tax benefits is as follows (in thousands):

	2016			2015
Gross unrecognized tax benefits at beginning of year	$	1,158		$	1,165
Gross decreases in tax positions for prior years		—			—
Gross increases in tax positions for current year		490			237
Settlements		(100	)		—
Lapse of statute of limitations		(268	)		(244	)

Gross unrecognized tax benefits at end of year	$	1,280		$	1,158

The Company recognizes interest and penalties related to uncertain tax positions as a component of income tax expense. During the years ended December 31, 2016, 2015 and 2014, the Company recorded interest related to unrecognized tax benefits of approximately $0.1 million, $0.2 million, and $0.3 million, respectively. The Company had approximately $0.6 million and $1.0 million of accrued interest and penalties at December 31, 2016 and 2015, respectively. The total amount of unrecognized tax benefits, which is recorded within claims, insurance and other liabilities on the balance sheet, that would affect the Company’s effective tax rate if recognized is $1.3 million and $1.2 million as of December 31, 2016 and 2015, respectively. The Company paid cash for income taxes of $5.4 million, $16.4 million, and $20.8 million in 2016, 2015 and 2014, respectively.

The Company does not anticipate total unrecognized tax benefits will significantly change during the next twelve months due to the settlements of audits and the expiration of statutes of limitations.

As a result of legislation enacted in the fourth quarter of 2015, the Company recognized tax credits for alternative fuel usage of approximately $1.0 million in 2016 and 2015.