Income Tax (Tables)

12 Months Ended

Dec. 31, 2016

The components of the provision for income tax expense are as follows (in millions):

The statutory federal income tax rate applied to pre-tax book income reconciles to income tax expense as follows in millions):


	Year Ended December 31,
	2016		2015		2014
Expected income tax expense (benefit) based on federal statutory rate of 35%	$	(159.4)	$	(116.0)	$	70.7
State income taxes, net of federal benefit and other		(9.8)		(7.7)		5.7
Goodwill impairment		173.8		149.4		—
Total income tax expense	$	4.6	$	25.7	$	76.4

Our deferred income tax assets and liabilities as of December 31, 2016 and 2015 are as follows (in millions):


	Year Ended December 31,
	2016		2015
Deferred income tax assets:
Asset retirement obligations and other	$	0.9	$	2.3
State net operating loss carryforward		6.5		3.6
Federal net operating loss carryforward		59.5		20.9
Total deferred tax assets		66.9		26.8
Deferred tax liabilities:
Property, plant, equipment, and intangible assets		(609.5)		(557.6)
Other		—		(1.3)
Total deferred tax liabilities		(609.5)		(558.9)
Deferred tax liability, net	$	(542.6)	$	(532.1)

(1)

Includes our investment in the Partnership, and primarily relates to differences between the book and tax bases of property, plant and equipment.

A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows (in millions):


	Year Ended December 31,
	2016		2015		2014
Beginning balance, January 1	$	1.5	$	2.0	$	—
Unrecognized tax positions assumed in merger		—		—		3.8
Decrease due to prior year tax positions		(1.5)		(0.5)		(2.0)
Increases due to current year tax positions		—		—		0.2
Ending balance, December 31	$	—	$	1.5	$	2.0