(6) Taxes on Income

Earnings before taxes on income and details of the provision for taxes on income for the years ended December 31, 2016, 2015 and 2014 were as follows (in thousands):

	2016		2015		2014
Earnings before taxes on income — United States	$	227,746	$	361,712	$	454,390

Provision for taxes on income:
Federal:
Current	$	28,919	$	64,707	$	81,953
Deferred		49,685		59,582		72,920
State and local		6,338		9,453		14,909
	$	84,942	$	133,742	$	169,782

During the three years ended December 31, 2016, 2015 and 2014, the tax benefit (expense) related to the exercise of stock options and the issuance of restricted stock that were allocated directly to additional paid-in capital were $(824,000), $964,000 and $6,119,000, respectively.

The Company’s provision for taxes on income varied from the statutory federal income tax rate for the years ended December 31, 2016, 2015 and 2014 due to the following:

	2016			2015			2014
United States income tax statutory rate		35.0	%		35.0	%		35.0	%
State and local taxes, net of federal benefit		1.8			1.7			2.2
Other – net		.5			.3			.2
		37.3	%		37.0	%		37.4	%

The tax effects of temporary differences that give rise to significant portions of the current deferred tax assets and non-current deferred tax assets and liabilities at December 31, 2016 and 2015 were as follows (in thousands):

	2016			2015
Current deferred tax assets:
Compensated absences	$	739		$	829
Allowance for doubtful accounts		2,534			3,288
Insurance accruals		6,218			4,234
Other		4,113			3,372
	$	13,604		$	11,723

Non-current deferred tax assets and liabilities:
Deferred tax assets:
Postretirement health care benefits	$	2,234		$	2,501
Insurance accruals		2,910			3,410
Deferred compensation		11,124			10,534
Unrealized loss on defined benefit plans		28,832			25,245
Operating loss carryforwards		7,846			5,188
Other		21,622			20,702
Valuation allowances		(7,417)			(4,716)
		67,151			62,864

Deferred tax liabilities:
Property		(654,751	)		(604,737	)
Deferred state taxes		(54,812	)		(53,542	)
Pension benefits		(2,799	)		(8,471	)
Goodwill and other intangibles		(51,551	)		(44,185	)
Other		(22,295	)		(21,737	)
		(786,208	)		(732,672	)
	$	(719,057	)	$	(669,808	)

The Company has determined that it is more likely than not that all federal deferred tax assets at December 31, 2016 will be realized, including its operating loss carryforwards of $429,000 that expire in various amounts through 2030.

The valuation allowance for state deferred tax assets as of December 31, 2016 and 2015 was $7,417,000 and $4,716,000, respectively, related to the Company’s state net operating loss carryforwards based on the Company’s determination that it is more likely than not that the deferred tax assets will not be realized. Expiration of these state net operating loss carryforwards vary by state through 2036 and none will expire in fiscal 2017. Total deferred tax assets were $88,172,000 and $79,303,000 as of December 31, 2016 and 2015, respectively. Total deferred tax assets, net of valuation allowances, were $80,755,000 and $74,587,000 as of December 31, 2016 and 2015, respectively.

The Company or one of its subsidiaries files income tax returns in the United States federal jurisdiction and various state jurisdictions. The Company is currently open to audit under the statute of limitations by the Internal Revenue Service for the 2013 through 2015 tax years. With few exceptions, the Company and its subsidiaries’ state income tax returns are open to audit under the statute of limitations for the 2010 through 2015 tax years.

As of December 31, 2016, the Company has provided a liability of $2,573,000 for unrecognized tax benefits related to various income tax issues which includes interest and penalties. The amount that would impact the Company’s effective tax rate, if recognized, is $1,737,000, with the difference between the total amount of unrecognized tax benefits and the amount that would impact the effective tax rate being primarily related to the federal tax benefit of state income tax items. It is not reasonably possible to determine if the liability for unrecognized tax benefits will significantly change prior to December 31, 2017 due to the uncertainty of possible examination results.

A reconciliation of the beginning and ending amount of the liability for unrecognized tax benefits for the years ended December 31, 2016, 2015 and 2014, is as follows (in thousands):

	2016			2015			2014
Balance at beginning of year	$	1,958		$	1,171		$	949
Additions based on tax positions related to the current year		187			339			470
Additions for tax positions of prior years		867			785			39
Reductions for tax positions of prior years		(441	)		(337	)		(287	)
Settlements		(552	)		—			—
Balance at end of year	$	2,019		$	1,958		$	1,171

The Company accounts for interest and penalties related to uncertain tax positions as part of its provision for federal and state income taxes. The Company recognized net expense of $88,000, $216,000 and $40,000 in interest and penalties for the years ended December 31, 2016, 2015 and 2014, respectively. The Company had $554,000, $522,000 and $306,000 of accrued liabilities for the payment of interest and penalties at December 31, 2016, 2015 and 2014, respectively.