Income Taxes - Income taxes relating to continuing operations and deferred taxes (Details) - USD ($) $ in Millions		12 Months Ended
	Dec. 22, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2008	Dec. 31, 2007
Income from continuing operations before income taxes by geographic region
U.S.		$ 390.3	$ 375.4	$ 316.7
Non-U.S.		213.8	172.8	191.4
Income from continuing operations before income taxes		604.1	548.2	508.1
Current:
Federal		(15.6)	(3.5)	(47.2)
State and local		(2.9)	4.2	4.7
Foreign		46.9	43.2	41.0
Total current		28.4	43.9	(1.5)
Deferred:
Federal		85.9	(150.5)	140.6
State and local		20.0	47.2	22.3
Foreign			(5.4)	(0.7)
Total deferred		105.9	(108.7)	162.2
Income taxes		$ 134.3	(64.8)	160.7
Reconciliation of income taxes from continuing operations at federal statutory rate
Federal statutory income tax rate (as a percent)	35.00%	21.00%			21.00%	35.00%
Income taxes at federal statutory rate of 35%		$ 126.9	191.9	177.8
State and local income taxes, net of federal taxes		13.8	13.7	14.7
Non-U.S. income taxed at other rates		1.9	(25.2)	(26.8)
Revaluation of U.S. deferreds			(301.6)
Deemed mandatory repatriation			54.8
SAB 118 Benefit		(11.6)
Other		3.3	1.6	(5.0)
Income taxes		134.3	(64.8)	160.7
Deferred Tax Assets
Accrued liabilities		48.7	53.6
Net operating loss and credit carryforwards		81.4	131.0
Other		27.9	24.0
Total deferred tax assets		158.0	208.6
Valuation allowance		(40.5)	(36.6)
Net deferred tax assets		117.5	172.0
Deferred Tax Liabilities
Depreciation and amortization		(188.0)	(178.1)
Partnership investments		(499.3)	(469.5)
Convertible notes			(1.5)
Other		(8.0)	(4.4)
Total deferred tax liabilities		(695.3)	(653.5)
Net deferred tax liabilities		(577.8)	(481.5)
Income from continuing operations before income taxes of non-U.S. subsidiaries		213.8	$ 172.8	$ 191.4
Amount of total temporary difference related to the excess of financial reporting basis over tax basis in the non-U.S. subsidiaries on which U.S. federal income taxes are not provided		$ 110.5