Condensed Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (25.1)	$ 40.6	$ 94.9	$ 107.2
Other comprehensive (loss) income:
Foreign currency translation adjustments	0.0	(0.8)	(0.1)	(4.8)
Unrealized gains (losses) on securities:
Gains (losses) arising during the year	(7.4)	(2.4)	91.3	(63.8)
Reclassification adjustment for losses included in net income	2.8	(2.4)	7.7	0.2
Other comprehensive (loss) income before tax	(4.6)	(5.6)	98.9	(68.4)
Income tax provision related to other comprehensive income (loss):
(Losses) gains arising during the year	(0.7)	(1.1)	15.1	(10.4)
Reclassification adjustment for losses included in net income	0.3	(0.3)	1.0	(0.1)
Income tax (benefit) provision related to other comprehensive (loss) income	(0.4)	(1.4)	16.1	(10.5)
Other comprehensive (loss) income, net of tax	(4.2)	(4.2)	82.8	(57.9)
Comprehensive (loss) income	$ (29.3)	$ 36.4	$ 177.7	$ 49.3

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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