Consolidated Statements of Shareholders' Equity - USD ($) $ in Millions	Total	Common shares	Additional paid-in surplus	Retained earnings	Accumulated other comprehensive (loss)	Parent	Non-controlling interests	Cumulative effect, period of adoption Retained earnings	Adjusted balance Retained earnings
Beginning balance at Dec. 31, 2018		$ 1.2	$ 1,089.1	$ 816.6	$ (202.4)			$ 0.0	$ 816.6
Changes in common shareholders' equity
Share-based compensation			4.5
Other, net			(0.1)
Net (loss) income	$ 112.3			112.3
Loss (income) attributable to non-controlling interests	(1.2)			(1.2)
Change in carrying value of Series B preference shares				(9.2)
Other, net				0.0
Net change in foreign currency translation	(26.7)				(26.7)
Ending balance at Jun. 30, 2019	1,787.1		1,093.5	918.5	(229.1)	$ 1,784.1	$ 3.0
Beginning balance at Mar. 31, 2019		1.2	1,090.2	911.8	(230.2)			0.0	911.8
Changes in common shareholders' equity
Share-based compensation			3.3
Other, net			0.0
Net (loss) income	8.2			8.2
Loss (income) attributable to non-controlling interests	(0.8)			(0.8)
Change in carrying value of Series B preference shares				(0.8)
Other, net				0.1
Net change in foreign currency translation	1.1				1.1
Ending balance at Jun. 30, 2019	1,787.1		1,093.5	918.5	(229.1)	1,784.1	3.0
Beginning balance at Dec. 31, 2019	1,642.8	1.2	1,098.2	778.5	(237.5)			(6.8)	771.7
Changes in common shareholders' equity
Share-based compensation			4.2
Other, net			0.0
Net (loss) income	(128.5)			(128.5)
Loss (income) attributable to non-controlling interests	0.0			0.0
Change in carrying value of Series B preference shares				16.8
Other, net				0.0
Net change in foreign currency translation	(6.4)				(6.4)
Ending balance at Jun. 30, 2020	1,522.2		1,102.4	660.0	(243.9)	1,519.7	2.5
Beginning balance at Mar. 31, 2020		$ 1.2	1,100.1	673.7	(300.9)			$ 0.0	$ 673.7
Changes in common shareholders' equity
Share-based compensation			2.3
Other, net			0.0
Net (loss) income	(7.2)			(7.2)
Loss (income) attributable to non-controlling interests	0.2			0.2
Change in carrying value of Series B preference shares				(6.6)
Other, net				(0.1)
Net change in foreign currency translation	57.0				57.0
Ending balance at Jun. 30, 2020	$ 1,522.2		$ 1,102.4	$ 660.0	$ (243.9)	$ 1,519.7	$ 2.5