Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Schedule of Income Tax Provision

The income tax provision was as follows:

	Year Ended December 31,
(Dollars in millions)	2020		2019		2018
Current:
Federal	$	108.9	$	40.0	$	30.3
State	50.3		24.0		11.5
	159.2		64.0		41.8
Deferred:
Federal	17.6		34.7		20.4
State	1.4		5.2		9.6
	19.0		39.9		30.0
Total	$	178.2	$	103.9	$	71.8

Schedule of Effective Income Tax Rate Reconciliation

The reconciliation between amounts computed using the federal income tax rate of 21% and our income tax provision is shown in the following tabulation:

	Year Ended December 31,
(Dollars in millions)	2020		2019		2018
Federal tax provision at statutory rate	$	136.2	$	78.8	$	70.9
State taxes, net of federal income tax benefit	40.4		23.6		16.1
Non-deductible items	2.8		2.6		1.5
Permanent differences related to stock compensation	(0.5)		0.2		(0.1)
Net change in valuation allowance	0.5		(0.5)		0.5
General business credits	(1.3)		(0.9)		(1.1)
Deferred remeasurement for change in statutory tax rate	—		—		(15.8)
Other	0.1		0.1		(0.2)
Income tax provision	$	178.2	$	103.9	$	71.8

Schedule of Deferred Tax Assets and Liabilities

Individually significant components of the deferred tax assets and (liabilities) are presented below:

	December 31,
(Dollars in millions)	2020		2019
Deferred tax assets:
Deferred revenue and cancellation reserves	$	64.2	$	48.4
Allowances and accruals, including state tax carryforward amounts	55.6		42.1
Lease liability	73.4		69.7
Credits and other	3.4		0.3
Valuation allowance	(1.1)		(0.6)
Total deferred tax assets	195.5		159.9
Deferred tax liabilities:
Inventories	(44.9)		(40.0)
Goodwill	(76.5)		(60.7)
Property and equipment, principally due to differences in depreciation	(139.0)		(113.6)
Right-of-use assets	(69.8)		(66.6)
Prepaid expenses and other	(11.6)		(10.1)
Total deferred tax liabilities	(341.8)		(291.0)
Total	$	(146.3)	$	(131.1)

Schedule of Unrecognized Tax Benefits

The following is a reconciliation of our unrecognized tax benefits for 2020:

(Dollars in millions)
Balance, December 31, 2019	$	—
Increase related to tax positions taken - current year	0.2
Balance, December 31, 2020	$	0.2

Summary of Open Tax Years

Open tax years at December 31, 2020 included the following:

Federal	2017 - 2020
24 states	2016 - 2020