Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Schedule of Components of Income Tax Expense (Benefit)

The components of the provision for income taxes as of December 31, 2017, 2016 and 2015, were as follows:



	(in millions)	2017			2016		2015
Current:
	Federal	$	19.3		$	24.4	$	5.5
	State and other	5.6			7.5		7.5
		24.9			31.9		13.0

Deferred:
	Federal	71.4			71.2		79.3
	State and other	6.7			5.6		5.5
	Impact of the Tax Cuts and Jobs Act	(229.5		)	—		—
		(151.4		)	76.8		84.8
Total provision for (benefit from) income taxes		$	(126.5	)	$	108.7	$	97.8

Schedule of Effective Income Tax Rate Reconciliation

The provision for income taxes as of December 31, 2017, 2016, and 2015 differed from the amounts computed using the federal statutory rate of 35% in effect for each year as follows:



		2017					2016				2015
	(in millions, except percentages)	Dollar Impact			Rate		Dollar Impact		Rate		Dollar Impact		Rate
Income tax at federal statutory rate		$	92.2		35.0	%	$	93.0	35.0	%	$	83.6	35.0	%
State tax, net of federal effect		8.6			3.3	%	10.5		3.9	%	10.3		4.3	%
Nondeductible meals and entertainment		3.4			1.3	%	3.4		1.3	%	3.6		1.5	%
Impact of the Tax Cuts and Jobs Act		(229.5		)	(87.1	)%	—		—		—		—
Other, net		(1.2		)	(0.5	)%	1.8		0.7	%	0.3		0.2	%
	Total provision for (benefit from) income taxes	$	(126.5	)	(48.0	)%	$	108.7	40.9	%	$	97.8	41.0	%

Schedule of Deferred Tax Assets and Liabilities

The components of the net deferred tax liability included in deferred income taxes in the consolidated balance sheets as of December 31, 2017 and 2016, were as follows:



(in millions)		2017			2016
Deferred tax assets:
Allowances for doubtful accounts		$	1.1		$	1.0
Compensation and employee benefits		15.6			21.5
Insurance and claims accruals		2.8			4.7
State net operating losses and credit carryforwards		17.7			14.0
Other		4.0			6.2
	Total gross deferred tax assets	41.2			47.4
Valuation allowance		(4.4		)	(2.8		)
	Total deferred tax assets, net of valuation allowance	36.8			44.6
Deferred tax liabilities:
Property and equipment		410.8			572.9
Prepaid expenses		3.6			5.1
Intangibles		8.7			5.2
Other		0.3			—
	Total gross deferred tax liabilities	423.4			583.2
Net deferred tax liability		$	386.6		$	538.6

Schedule of Unrecognized Tax Benefits Roll Forward

As of December 31, 2017, 2016, and 2015, a reconciliation of the beginning and ending amount of unrecognized tax benefits, which is recorded as other noncurrent liabilities in the consolidated balance sheets, is as follows:



(in millions)		2017		2016			2015
Gross unrecognized tax benefits - beginning of year		$	2.4	$	2.0		$	2.9
	Gross increases - tax positions related to current year	0.4		0.5			0.5
	Gross decreases - tax positions taken in prior years	—		(0.1		)	(1.1		)
	Settlements	—		—			(0.2		)
	Lapse of statutes	—		—			(0.1		)
Gross unrecognized tax benefits - end of year		$	2.8	$	2.4		$	2.0