Deferred tax assets and liabilities are determined based on the differences between the financial and tax basis of existing assets and liabilities using the currently enacted tax rates in effect for the year in which the differences are expected to reverse.

The provision for income taxes on income consisted of the following in 2014, 2013 and 2012:


	2014			2013			2012
Current:
Federal	$	5,953		$	3,960		$	202
State		707			415			321
Foreign		1,853			1,025			1,798
		8,513			5,400			2,321
Deferred:
Federal		283			(238	)		1,095
State		32			(28	)		122
Foreign		(168	)		41			(7	)
		147			(225	)		1,210
	$	8,660		$	5,175		$	3,531

The principal differences between the federal statutory tax rate and the income tax expense in 2014, 2013 and 2012:


	2014			2013			2012
Federal statutory tax rate		35.0	%		35.0	%		35.0	%
State taxes, net of federal tax benefit		3.7	%		3.7	%		4.0	%
Excess of foreign tax over US tax on foreign income		0.1	%		0.3	%		0.6	%
Domestic Tax Credits		(1.4	)%		(1.5	)%		(10.8	)%
Other		(0.5	)%		(0.2	)%		(0.9	)%
Effective tax rate		36.9	%		37.3	%		27.9	%

Income taxes for 2012 include $1,361 of income tax benefits resulting primarily from Federal Domestic Activity Deductions, as well as Federal Research and Development and other tax credits recognized during the period.

Deferred income tax assets and liabilities reflect the impact of temporary differences between the amounts of assets and liabilities for financial reporting and income tax reporting purposes. Temporary differences and carry forwards which give rise to deferred tax assets and liabilities at December 31, 2014 and 2013 are as follows:


	2014		2013
Deferred tax assets:
Allowance for doubtful accounts	$	94	$	95
Accruals and reserves		3,767		3,739
Other		222		54
Total deferred tax assets		4,083		3,888
Deferred tax liabilities:
Property, plant, and equipment		2,184		1,842
Total deferred tax liabilities		2,184		1,842
Net deferred tax asset	$	1,899	$	2,046

As of December 31, 2014, the Company has no federal or state net operating loss carryforwards.

At December 31, 2014 and 2013, the Company had no unrecognized tax positions. The Company does not expect its unrecognized tax positions to change significantly in the next twelve months. If unrecognized tax positions existed, the interest and penalties related to the unrecognized tax positions would be recorded as income tax expense in the consolidated statements of income.

The Company is subject to United States federal income taxes, as well as income taxes in various states and foreign jurisdictions. The Company’s tax years 2011 through 2013 remain open to examination for U.S. Federal and state income taxes.