Supplemental Guarantor Information Supplemental Guarantor Information (Condensed Consolidating Statement of Cash Flows) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Net cash used by operating activities	$ (142.3)	$ (66.3)
Cash flow from investing activities:
Capital expenditures	(20.2)	(12.1)
Payments for acquisitions	(5.8)	0.0	$ (5.6)
Proceeds from maturities of investments	104.6	84.9
Payments for purchases of investments	(45.5)	(95.1)
Proceeds from sale of assets	9.2	2.0
Increase in certain other assets	(3.2)	(8.7)
Capital contributions and loans paid	0.0	0.0
Proceeds from intercompany loans	0.0	0.0
Net cash used by investing activities	39.1	(29.0)
Cash flow from financing activities:
Dividends paid	(7.7)	(7.6)
Revolving credit facility (repayments) borrowings, net	(75.0)	20.0
Other debt borrowings	26.0	19.1
Other debt repayments	(31.7)	(84.0)
Distributions and payments to noncontrolling interest holders	(0.5)	(15.7)
Issuance of common shares	0.0	0.3
Repurchase of common shares	(2.5)	(4.6)
Capital contributions received and loans incurred	0.0	0.0
Payments on intercompany loans	0.0	0.0
Net cash provided by financing activities	(91.4)	(72.5)
Effect of exchange rate changes on cash and cash equivalents	21.5	5.2
Increase (decrease) in cash and cash equivalents	(173.1)	(162.6)
Cash and cash equivalents at the beginning of the period	535.2	652.7	652.7
Cash and cash equivalents at the end of the period	362.1	490.1	535.2
Reportable Legal Entities [Member] | Parent Company [Member]
Net cash used by operating activities	(31.8)	(112.3)
Cash flow from investing activities:
Capital expenditures	(2.3)	(1.8)
Payments for acquisitions	0.0
Proceeds from maturities of investments	1.0	0.8
Payments for purchases of investments	0.0	0.0
Proceeds from sale of assets	8.6	0.0
Increase in certain other assets	(2.5)	(4.9)
Capital contributions and loans paid	(12.1)	(164.7)
Proceeds from intercompany loans	9.3	162.3
Net cash used by investing activities	2.0	(8.3)
Cash flow from financing activities:
Dividends paid	(7.7)	(7.6)
Revolving credit facility (repayments) borrowings, net	0.0	20.0
Other debt borrowings	0.0	0.0
Other debt repayments	(11.3)	(7.8)
Distributions and payments to noncontrolling interest holders	0.0	0.0
Issuance of common shares		0.3
Repurchase of common shares	(2.5)	(4.6)
Capital contributions received and loans incurred	0.0	0.0
Payments on intercompany loans	0.0	0.0
Net cash provided by financing activities	(21.5)	0.3
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Increase (decrease) in cash and cash equivalents	(51.3)	(120.3)
Cash and cash equivalents at the beginning of the period	58.5	138.4	138.4
Cash and cash equivalents at the end of the period	7.2	18.1	58.5
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Net cash used by operating activities	(3.0)	(2.2)
Cash flow from investing activities:
Capital expenditures	(0.1)	0.0
Payments for acquisitions	0.0
Proceeds from maturities of investments	0.0	0.0
Payments for purchases of investments	0.0	0.0
Proceeds from sale of assets	0.0	0.0
Increase in certain other assets	0.8	4.2
Capital contributions and loans paid	0.0	0.0
Proceeds from intercompany loans	0.0	0.0
Net cash used by investing activities	0.7	4.2
Cash flow from financing activities:
Dividends paid	0.0	0.0
Revolving credit facility (repayments) borrowings, net	0.0	0.0
Other debt borrowings	0.0	0.0
Other debt repayments	(0.1)	(0.3)
Distributions and payments to noncontrolling interest holders	0.0	0.0
Issuance of common shares		0.0
Repurchase of common shares	0.0	0.0
Capital contributions received and loans incurred	12.1	17.8
Payments on intercompany loans	(9.3)	(19.6)
Net cash provided by financing activities	2.7	(2.1)
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Increase (decrease) in cash and cash equivalents	0.4	(0.1)
Cash and cash equivalents at the beginning of the period	2.3	2.3	2.3
Cash and cash equivalents at the end of the period	2.7	2.2	2.3
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Net cash used by operating activities	(107.5)	5.1
Cash flow from investing activities:
Capital expenditures	(17.8)	(10.3)
Payments for acquisitions	(5.8)
Proceeds from maturities of investments	103.6	84.1
Payments for purchases of investments	(45.5)	(95.1)
Proceeds from sale of assets	0.6	2.0
Increase in certain other assets	(1.5)	(8.0)
Capital contributions and loans paid	0.0	0.0
Proceeds from intercompany loans	0.0	0.0
Net cash used by investing activities	33.6	(27.3)
Cash flow from financing activities:
Dividends paid	0.0	0.0
Revolving credit facility (repayments) borrowings, net	(75.0)	0.0
Other debt borrowings	26.0	62.2
Other debt repayments	(20.3)	(75.9)
Distributions and payments to noncontrolling interest holders	(0.5)	(15.7)
Issuance of common shares		0.0
Repurchase of common shares	0.0	0.0
Capital contributions received and loans incurred	0.0	146.9
Payments on intercompany loans	0.0	(142.7)
Net cash provided by financing activities	(69.8)	(25.2)
Effect of exchange rate changes on cash and cash equivalents	21.5	5.2
Increase (decrease) in cash and cash equivalents	(122.2)	(42.2)
Cash and cash equivalents at the beginning of the period	474.4	512.0	512.0
Cash and cash equivalents at the end of the period	352.2	469.8	474.4
Consolidation, Eliminations [Member]
Net cash used by operating activities	0.0	43.1
Cash flow from investing activities:
Capital expenditures	0.0	0.0
Payments for acquisitions	0.0
Proceeds from maturities of investments	0.0	0.0
Payments for purchases of investments	0.0	0.0
Proceeds from sale of assets	0.0	0.0
Increase in certain other assets	0.0	0.0
Capital contributions and loans paid	12.1	164.7
Proceeds from intercompany loans	(9.3)	(162.3)
Net cash used by investing activities	2.8	2.4
Cash flow from financing activities:
Dividends paid	0.0	0.0
Revolving credit facility (repayments) borrowings, net	0.0	0.0
Other debt borrowings	0.0	(43.1)
Other debt repayments	0.0	0.0
Distributions and payments to noncontrolling interest holders	0.0	0.0
Issuance of common shares		0.0
Repurchase of common shares	0.0	0.0
Capital contributions received and loans incurred	(12.1)	(164.7)
Payments on intercompany loans	9.3	162.3
Net cash provided by financing activities	(2.8)	(45.5)
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Increase (decrease) in cash and cash equivalents	0.0	0.0
Cash and cash equivalents at the beginning of the period	0.0	0.0	0.0
Cash and cash equivalents at the end of the period	$ 0.0	$ 0.0	$ 0.0