Details of income tax provisions and deferred income taxes from continuing operations are provided in the following tables.

The components of income tax provisions and benefits were as follows:



	Year Ended December 31,
	2016			2015			2014
Federal income tax provision (benefit)	(in millions)
Current	$	(55.5	)	$	(112.3	)	$	(324.0	)
Deferred	(614.3		)	34.5			110.3
State income tax provision (benefit)
Current	(1.5		)	(6.6		)	(15.5		)
Deferred	(36.9		)	(9.2		)	(3.3		)
Total income tax provision (benefit)	$	(708.2	)	$	(93.6	)	$	(232.5	)

The difference between the statutory federal income tax rate and the Company's effective income tax rate is explained as follows:



	Year Ended December 31,
	2016		2015		2014
Federal income taxes statutory rate	35.0	%	35.0	%	35.0	%
Increase (decrease) in rate as a result of:
State income taxes, net of federal income tax benefit	2.4	%	4.2	%	(1.5	)%
State rate change	(1.1	)%	—	%	3.4	%
Penalties	—	%	(0.3	)%	—	%
Return to provision adjustment	—	%	(0.3	)%	(0.4	)%
Other	—	%	(0.1	)%	(0.3	)%
Effective income tax rate	36.3	%	38.5	%	36.2	%

Significant components of the Company's deferred income taxes were as follows:



	December 31,
	2016		2015
Deferred tax liabilities	(in millions)
Property, plant and equipment	$	1,135.0	$	1,531.0
Commodity price derivatives	—		60.4
Total deferred tax liabilities	1,135.0		1,591.4
Deferred tax assets
Net operating loss and tax credit carryforwards	$	161.6	$	51.9
Employee benefits and compensation costs	49.0		43.6
Bonus and vacation accrual	11.4		7.0
Commodity price derivatives	74.3		—
Other	12.8		9.1
Total deferred tax assets	309.1		111.6
Net deferred income tax liability	$	825.9	$	1,479.8
Balance sheet classification
Deferred income tax liability – noncurrent	825.9		1,479.8
Net deferred income tax liability	$	825.9	$	1,479.8

The amounts and expiration dates of net operating loss and tax credit carryforwards at December 31, 2016, are as follows:



	Expiration Dates	Amounts
		(in millions)
State net operating loss and tax credit carryforwards	2017-2033	$	53.6
State net operating loss valuation allowance		(20.6		)
U.S. net operating loss	2036	109.1
U.S. alternative minimum tax credit	Indefinite	19.5
Total		$	161.6

The valuation allowance of $20.6 million was established in 2014 against the available state net operating loss and is related primarily to losses incurred in Oklahoma. Due to the 2014 property sales in the Other Southern area in which the Company sold its interests in most of its properties in Oklahoma, the Company does not forecast sufficient taxable income to utilize the net operating loss in Oklahoma.

Unrecognized Tax Benefit

As of December 31, 2016 and 2015, QEP had $15.6 million of unrecognized tax benefits related to uncertain tax positions for asset sales that occurred in 2014, which were recorded within "Other long-term liabilities" on the Consolidated Balance Sheet. The uncertain tax positions the Company reported during the year ended December 31, 2016 and 2015, were expensed during the year ended December 31, 2014. The benefits of uncertain tax positions taken or expected to be taken on income tax returns is recognized in the consolidated financial statements at the largest amount that is more likely than not to be sustained upon examination by the relevant taxing authorities. Our policy is to recognize any interest expense related to uncertain tax positions in "Interest expense" on the Consolidated Statement of Operations and to recognize any penalties related to uncertain tax positions in "General and administrative" expense on the Consolidated Statements of Operations. During the year ended December 31, 2016, the Company incurred $0.7 million of estimated interest expense and $0.6 million of estimated penalties related to uncertain tax positions. During the year ended December 31, 2015, the Company incurred $0.5 million of estimated interest expense and $2.2 million of estimated penalties related to uncertain tax positions.

The following is a reconciliation of our beginning and ending amounts of unrecognized tax benefits for the years ended December 31, 2016 and 2015:



	Unrecognized Tax Benefits
	2016		2015
	(in millions)
Balance as of January 1,	$	15.6	$	—
Additions for tax positions taken during the current period	—		15.6
Balance as of December 31,	$	15.6	$	15.6

As of December 31, 2016 and 2015, QEP had approximately $15.6 million of unrecognized tax benefit that would impact its effective tax rate if recognized.