Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 6.7	$ (54.1)	$ (14.1)
Other comprehensive income (loss):
Foreign currency translation adjustments	2.6	(15.3)	(0.2)
Defined benefit pension plans:
Net gain arising during the year	1.9	(0.6)	(1.8)
Unrealized gains (losses) on fixed maturity securities:
(Losses) gains arising during the year	(94.7)	95.2	88.0
Reclassification adjustment for losses (gains) included in net income	(12.2)	(12.8)	9.9
Other comprehensive (loss) income before tax	(102.4)	66.5	95.9
Defined benefit pension plans:
Net gain arising during the year	0.4	(0.1)	(0.4)
Unrealized gains (losses) on fixed maturity securities:
(Losses) gains arising during the year	(17.3)	16.5	14.2
Reclassification adjustment for (gains) losses included in net income	(4.2)	0.0	1.2
Income tax (benefit) provision related to other comprehensive income (loss)	(21.1)	16.4	15.0
Other comprehensive (loss) income, net of tax	(81.3)	50.1	80.9
Comprehensive (loss) income	$ (74.6)	$ (4.0)	$ 66.8