Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Schedule of Income before Income Tax, Domestic and Foreign

Income before income taxes was taxed under the following jurisdictions:

	Years Ended December 31,
(in millions)	2017		2016		2015
Domestic	$	607.1	$	635.5	$	626.4
Foreign	53.2		36.9		20.6
Total	$	660.3	$	672.4	$	647.0

Schedule of Components of Income Tax Expense (Benefit)

Components of Income tax expense (benefit) consist of the following:

	Years Ended December 31,
(in millions)	2017			2016			2015
Current:
Federal	$	258.9		$	295.7		$	258.5
State	29.8			34.9			28.6
Foreign	21.3			16.8			10.1
Total current	310.0			347.4			297.2
Deferred:
Domestic	(168.0		)	(90.5		)	(48.5		)
Foreign	(4.7		)	(8.9		)	(4.8		)
Total deferred	(172.7		)	(99.4		)	(53.3		)
Income tax expense	$	137.3		$	248.0		$	243.9

Schedule of Effective Income Tax Rate Reconciliation

The reconciliation between the statutory tax rate expressed as a percentage of income before income taxes and the effective tax rate is as follows:

	Years Ended December 31,
(dollars in millions)	2017					2016					2015
Statutory federal income tax rate	$	231.1		35.0	%	$	235.4		35.0	%	$	226.4		35.0	%
State taxes, net of federal effect(1)	18.3			2.8		17.8			2.6		16.5			2.6
Excess tax benefit of equity awards	(36.2		)	(5.5	)	(1.6		)	(0.2	)	—			—
Effect of rates different than statutory	(6.3		)	(1.0	)	(4.5		)	(0.7	)	(1.9		)	(0.3	)
Foreign withholding tax	1.0			0.2		0.8			0.1		3.3			0.5
Effect of UK tax rate change on deferred taxes	—			—		(1.5		)	(0.2	)	(4.0		)	(0.6	)
Effect of US Tax Cuts and Jobs Act on Deferred Taxes and Mandatory Repatriation Tax	(75.5		)	(11.4	)	—			—		—			—
Other	4.9			0.7		1.6			0.3		3.6			0.5
Effective tax rate	$	137.3		20.8	%	$	248.0		36.9	%	$	243.9		37.7	%

(1) The impact of state taxes on excess tax benefits of equity awards and the US Tax Cuts and Jobs Act are presented on the respective separate lines in the effective tax rate reconciliation.

Schedule of Deferred Tax Assets and Liabilities

The tax effect of temporary differences that give rise to the net deferred income tax liabilities is presented below:

	December 31,
(in millions)	2017		2016
Deferred tax assets:
Equity compensation plans	$	18.7	$	29.2
Payroll and benefits	8.0		22.7
Deferred interest	6.8		13.9
Net operating loss and credit carryforwards, net	28.1		12.7
Rent	7.4		11.0
Accounts receivable	5.4		8.3
Other	8.0		6.2
Trade credits	1.5		0.6
Total deferred tax assets	83.9		104.6
Deferred tax liabilities:
Software and intangibles	194.5		337.4
Deferred income	18.6		58.3
International investments	19.2		31.3
Property and equipment	20.4		30.3
Other	12.0		15.3
Total deferred tax liabilities	264.7		472.6
Deferred tax asset valuation allowance	15.5		1.2
Net deferred tax liabilities	$	196.3	$	369.2