Income Taxes - Pre-tax Income and Provision (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Continuing operations
U.S. domestic	$ 484.7	$ 352.2	$ 356.5
Foreign	110.6	93.7	72.5
Income from continuing operations before income taxes	595.3	445.9	429.0
Discontinued operations
U.S. domestic	(1.8)	299.8	39.1
Foreign	0.0	0.3	0.5
Income from discontinued operations before income taxes	(1.8)	300.1	39.6
Total income before income taxes	593.5	746.0	468.6
Current provision:
Federal and State	105.9	62.0	116.5
Foreign	23.4	25.9	28.4
Total current provision	129.3	87.9	144.9
Deferred provision (benefit):
Federal and State	(6.9)	7.9	(62.7)
Foreign	(0.8)	(8.5)	6.2
Total deferred (benefit) provision	(7.7)	(0.6)	(56.5)
Total provision for income taxes	121.6	87.3	88.4
Reconciliation of taxes from continuing operations
Taxes at U.S. statutory rate	125.0	93.6	150.1
State and local taxes, net of federal income tax benefit	15.2	10.8	9.5
Foreign earnings taxed at different rates	0.8	1.1	(6.7)
Change in unrecognized tax benefit	(2.8)	(7.8)	0.9
Return to provision adjustments	(7.6)	(2.3)	(0.7)
Benefit for domestic manufacturing deduction	0.0	0.0	(9.7)
Tax credits	(5.2)	(3.0)	(2.3)
Impact of U.S. tax reform	0.0	(3.3)	(57.7)
Change in investment assertion on foreign earnings	0.0	0.0	5.1
Other, net	(3.8)	(1.8)	(0.1)
Provision for income taxes	$ 121.6	$ 87.3	$ 88.4
Effective income tax rate on continuing operations (as a percent)	20.40%	19.60%	20.60%
Income Taxes Paid, Net [Abstract]
Cash payments for income taxes, net of refunds	$ 120.6	$ 203.0	$ 142.8