INCOME TAX

The income tax provision (benefit) on income from operations consists of the following:



	Years Ended December 31,
	2016			2015			2014
Current:
Federal	$	41,366		$	44,841		$	34,504
State	7,023			6,670			4,827
	48,389			51,511			39,331
Deferred	(28,939		)	(7,956		)	(3,804		)
	$	19,450		$	43,555		$	35,527

Reconciliation of the U.S. statutory income tax rate to our effective income tax expense rate for operations follows:



	Years Ended December 31,
	2016			2015			2014
Federal income tax expense at statutory rate	$	45,257		$	37,949		$	33,064
State income tax, net of federal income tax benefit	4,807			3,715			2,867
Domestic production activities deduction	(3,947		)	(466		)	(1,720		)
Excess tax benefits related to stock option exercises	(29,582		)	—			—
Non-deductible business expenses	2,979			2,414			1,485
Other, net	(64		)	(57		)	(169		)
	$	19,450		$	43,555		$	35,527

Due to the adoption of ASU No. 2016-09, federal and state excess tax benefits from stock option exercises for the year ended December 31, 2016 are reflected as a reduction of the provision for income taxes, whereas they were previously accounted for as an increase to shareholders’ equity. See Note 1 "Summary of Significant Accounting Policies" for additional information related to this adoption.

The tax effects of the major items recorded as deferred tax assets and liabilities as of December 31 are:



	2016			2015
Deferred income tax assets:
Operating expenses not currently deductible	$	18,721		$	9,953
Stock option and other employee benefit plans	19,665			13,504
Capital loss and credit carryforward	—			179
Total deferred income tax assets	38,386			23,636
Deferred income tax liabilities:
Intangible assets	(103,754		)	(111,653		)
Property and equipment	(3,207		)	(2,781		)
Other	(204		)	(228		)
Total deferred income tax liabilities	(107,165		)	(114,662		)
Net deferred income tax liabilities	$	(68,779	)	$	(91,026	)

Although realization is not assured, we believe it is more likely than not that all the deferred tax assets will be realized. Accordingly, we believe no valuation allowance is required for the deferred tax assets. However, the amount of the deferred tax asset considered realizable could be adjusted in the future if estimates of reversing taxable temporary differences are revised. There were no unrecognized tax benefits during any of the reported periods.

The Internal Revenue Service (“IRS”) is examining our U.S. income tax return for the year 2012. As of February 21, 2017, no significant adjustments have been proposed by any taxing jurisdiction. We are unable to make a reasonable estimate as to when cash settlements, if any, will occur.

We are subject to U.S. federal tax as well as income tax of multiple state and local jurisdictions. We are no longer subject to United States federal income tax or state and local income tax examinations for years before 2011.

We paid income taxes, net of refunds received, of $30.2 million in 2016, $27.3 million in 2015, and $10.2 million in 2014.