Guarantors - Condensed Consolidating Statements of Operations and Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Condensed Consolidating Statements of Operations
Revenue	$ 245.9	$ 225.0
Total operating expenses	232.7	213.2
Operating income	13.2	11.8
Interest expense, net	(16.0)	(23.7)
Gain on marketable equity investment	14.7	101.2
Foreign currency and derivative gains, net	5.1	0.0
Loss on early extinguishment of debt	(3.4)	0.0
Other expense	(0.1)	(0.1)
Net income before income taxes	13.5	89.2
Income tax benefit	1.2	0.2
Equity earnings (loss) related to investment in subsidiaries	0.0	0.0
Net income (loss)	14.7	89.4
Other comprehensive loss	(25.1)	3.3
Comprehensive (loss) income	(10.4)	92.7
Eliminations/Consolidations
Condensed Consolidating Statements of Operations
Revenue	0.0	0.0
Total operating expenses	0.0	0.0
Operating income	0.0	0.0
Interest expense, net	6.0	9.2
Gain on marketable equity investment	0.0	0.0
Foreign currency and derivative gains, net	0.0
Loss on early extinguishment of debt	0.0
Other expense	0.0	0.0
Net income before income taxes	6.0	9.2
Income tax benefit	0.0	0.0
Equity earnings (loss) related to investment in subsidiaries	12.0	(197.6)
Net income (loss)	18.0	(188.4)
Other comprehensive loss	0.0	0.0
Comprehensive (loss) income	18.0	(188.4)
General Partner
Condensed Consolidating Statements of Operations
Revenue	0.0	0.0
Total operating expenses	0.0	0.0
Operating income	0.0	0.0
Interest expense, net	0.0	0.0
Gain on marketable equity investment	0.0	0.0
Foreign currency and derivative gains, net	0.0
Loss on early extinguishment of debt	0.0
Other expense	0.0	0.0
Net income before income taxes	0.0	0.0
Income tax benefit	0.0	0.0
Equity earnings (loss) related to investment in subsidiaries	(0.1)	0.8
Net income (loss)	(0.1)	0.8
Other comprehensive loss	0.0	0.0
Comprehensive (loss) income	(0.1)	0.8
Parent Guarantor
Condensed Consolidating Statements of Operations
Revenue	0.0	0.0
Total operating expenses	0.0	0.0
Operating income	0.0	0.0
Interest expense, net	0.0	0.0
Gain on marketable equity investment	0.0	0.0
Foreign currency and derivative gains, net	0.0
Loss on early extinguishment of debt	0.0
Other expense	0.0	0.0
Net income before income taxes	0.0	0.0
Income tax benefit	0.0	0.0
Equity earnings (loss) related to investment in subsidiaries	(16.4)	83.5
Net income (loss)	(16.4)	83.5
Other comprehensive loss	0.0	0.0
Comprehensive (loss) income	(16.4)	83.5
LP Co-issuer
Condensed Consolidating Statements of Operations
Revenue	0.0	0.0
Total operating expenses	0.0	0.0
Operating income	0.0	0.0
Interest expense, net	(21.5)	(32.5)
Gain on marketable equity investment	0.0	0.0
Foreign currency and derivative gains, net	5.1
Loss on early extinguishment of debt	(3.4)
Other expense	0.0	0.0
Net income before income taxes	(19.8)	(32.5)
Income tax benefit	0.0	0.0
Equity earnings (loss) related to investment in subsidiaries	4.5	113.3
Net income (loss)	(15.3)	80.8
Other comprehensive loss	(1.1)	2.7
Comprehensive (loss) income	(16.4)	83.5
Finance Co-issuer
Condensed Consolidating Statements of Operations
Revenue	0.0	0.0
Total operating expenses	0.0	0.0
Operating income	0.0	0.0
Interest expense, net	0.0	0.0
Gain on marketable equity investment	0.0	0.0
Foreign currency and derivative gains, net	0.0
Loss on early extinguishment of debt	0.0
Other expense	0.0	0.0
Net income before income taxes	0.0	0.0
Income tax benefit	0.0	0.0
Equity earnings (loss) related to investment in subsidiaries	0.0	0.0
Net income (loss)	0.0	0.0
Other comprehensive loss	0.0	0.0
Comprehensive (loss) income	0.0	0.0
Guarantor Subsidiaries
Condensed Consolidating Statements of Operations
Revenue		209.2
Total operating expenses		189.3
Operating income		19.9
Interest expense, net		0.0
Gain on marketable equity investment		0.0
Other expense		0.0
Net income before income taxes		19.9
Income tax benefit		(0.8)
Equity earnings (loss) related to investment in subsidiaries		0.0
Net income (loss)		19.1
Other comprehensive loss		0.0
Comprehensive (loss) income		19.1
Non-Guarantors
Condensed Consolidating Statements of Operations
Revenue	245.9	15.8
Total operating expenses	232.7	23.9
Operating income	13.2	(8.1)
Interest expense, net	(0.5)	(0.4)
Gain on marketable equity investment	14.7	101.2
Foreign currency and derivative gains, net	0.0
Loss on early extinguishment of debt	0.0
Other expense	(0.1)	(0.1)
Net income before income taxes	27.3	92.6
Income tax benefit	1.2	1.0
Equity earnings (loss) related to investment in subsidiaries	0.0	0.0
Net income (loss)	28.5	93.6
Other comprehensive loss	(24.0)	0.6
Comprehensive (loss) income	$ 4.5	$ 94.2