Income Taxes

Provision for income taxes for the years ended December 31 consists of the following (in thousands):



	2015			2014			2013
Current:
Federal	$	363,803		$	394,904		$	281,938
State	37,811			30,997			23,701
Foreign	12,826			20,429			22,093
	414,440			446,330			327,732
Deferred:
Federal	(15,474		)	(5,743		)	51,509
State	(2,264		)	(3,155		)	(1,471		)
Foreign	1,254			1,277			2,542
	(16,484		)	(7,621		)	52,580
Total	$	397,956		$	438,709		$	380,312

The components of income before income taxes for the years ended December 31 were as follows (in thousands):



	2015		2014		2013
Domestic	$	1,101,427	$	1,196,335	$	1,042,317
Foreign	48,736		86,985		71,988
Total	$	1,150,163	$	1,283,320	$	1,114,305

The provision for income taxes differs from the amount that would be provided by applying the statutory U.S. corporate income tax rate due to the following items for the years ended December 31:



	2015		2014		2013
Provision at statutory rate	35.0	%	35.0	%	35.0	%
State taxes, net of federal benefit	1.8		1.7		1.6
Domestic manufacturing deduction	(2.1	)	(2.1	)	(1.7	)
Research and development credit	(0.4	)	(0.4	)	(0.9	)
Unrecognized tax benefits including interest and penalties	1.1		0.2		0.9
Valuation allowance adjustments	(0.1	)	(0.1	)	(0.3	)
Tax audit settlements	—		—		0.1
Adjustments for previously accrued taxes	(0.1	)	(0.3	)	(0.2	)
Other	(0.6	)	0.2		(0.4	)
Provision for income taxes	34.6	%	34.2	%	34.1	%

The principal components of the Company’s deferred tax assets and liabilities as of December 31 include the following (in thousands):



	2015			2014
Deferred tax assets:
Accruals not yet tax deductible	$	129,449		$	120,817
Pension and postretirement benefit plan obligations	126,952			104,723
Stock compensation	20,111			21,089
Net operating loss carryforward	38,250			41,927
Valuation allowance	(20,659		)	(25,462		)
Other, net	47,039			38,465
	341,142			301,559
Deferred tax liabilities:
Depreciation, tax in excess of book	(136,340		)	(128,117		)
Other	(2,419		)	(5,691		)
	(138,759		)	(133,808		)
Total	$	202,383		$	167,751

The Company reviews its deferred tax asset valuation allowances on a quarterly basis, or whenever events or changes in circumstances indicate that a review is required. In determining the requirement for a valuation allowance, the historical and projected financial results of the legal entity or consolidated group recording the net deferred tax asset is considered, along with any positive or negative evidence such as tax law changes. Since future financial results and tax law may differ from previous estimates, periodic adjustments to the Company’s valuation allowances may be necessary.

At December 31, 2015, the Company had approximately $339.4 million state net operating loss carry-forwards expiring in 2031. At December 31, 2015 the Company also had Wisconsin research and development credit carryforwards of $13.1 million expiring in 2028. The Company had a deferred tax asset of $26.0 million as of December 31, 2015 for the benefit of these losses and credits.

The Company has foreign net operating losses (NOL) totaling $12.2 million as of December 31, 2015. It has a valuation allowance of $20.7 million against the NOLs as well as other associated deferred tax assets of $8.5 million.

The Company recognizes interest and penalties related to unrecognized tax benefits in the provision for income taxes. Changes in the Company’s gross liability for unrecognized tax benefits, excluding interest and penalties, were as follows (in thousands):



	2015			2014
Unrecognized tax benefits, beginning of period	$	64,200		$	63,057
Increase in unrecognized tax benefits for tax positions taken in a prior period	9,149			900
Decrease in unrecognized tax benefits for tax positions taken in a prior period	(1,993		)	(4,989		)
Increase in unrecognized tax benefits for tax positions taken in the current period	6,302			5,876
Statute lapses	(2,465		)	—
Settlements with taxing authorities	(2,093		)	(644		)
Unrecognized tax benefits, end of period	$	73,100		$	64,200

The amount of unrecognized tax benefits as of December 31, 2015 that, if recognized, would affect the effective tax rate was $56.9 million.

The total gross amount of expense related to interest and penalties associated with unrecognized tax benefits recognized during 2015 in the Company’s Consolidated Statements of Income was $3.7 million.

The total gross amount of interest and penalties associated with unrecognized tax benefits recognized at December 31, 2015 in the Company’s Consolidated Balance Sheets was $28.7 million.

The Company does not expect a significant increase or decrease to the total amounts of unrecognized tax benefits related to continuing operations during the fiscal year ending December 31, 2016. However, the Company is under regular audit by tax authorities. The Company believes that it has appropriate support for the positions taken on its tax returns and that its annual tax provision includes amounts sufficient to pay any assessments. Nonetheless, the amounts ultimately paid, if any, upon resolution of the issues raised by the taxing authorities may differ materially from the amounts accrued for each year.

The Company or one of its subsidiaries files income tax returns in the United States federal and Wisconsin state jurisdictions and various other state and foreign jurisdictions. The Company is no longer subject to income tax examinations for Wisconsin state income taxes before 2011 or for United States federal income taxes before 2012.