Consolidated Statements of Shareholders' Equity - USD ($) $ in Millions	Common shares	Additional paid-in surplus	Retained earnings	Accumulated other comprehensive (loss)	Non-controlling interests	Total
Accumulated net foreign currency translation (losses)
Non-controlling interests						$ 0.2
Total common shareholders' equity at Dec. 31, 2017	$ 1.2	$ 1,197.9	$ 858.4	$ (140.5)
Capital contribution from former parent		1.4
Net income			43.3
Income attributable to non-controlling interests			(0.2)
Accrued dividends on Series A redeemable preference shares			(2.6)			(2.6)
Other, net			(0.1)
Balance at beginning of year at Dec. 31, 2017				(140.5)
Accumulated net foreign currency translation (losses)
Net change in foreign currency translation				(13.4)
Balance at end of year at Mar. 31, 2018				(153.9)
Total common shareholders' equity at Mar. 31, 2018		1,199.3	900.4	(153.9)		1,947.0
Cumulative effect of an accounting change			1.6
Accumulated net foreign currency translation (losses)
Non-controlling interests					$ 0.5	0.5
Total equity			860.0			1,947.5
Non-controlling interests						1.7
Total common shareholders' equity at Dec. 31, 2018	$ 1.2	1,089.1	816.6	(202.4)		1,704.5
Share-based compensation		1.2
Other, net		(0.1)
Net income			104.1
Income attributable to non-controlling interests			(0.4)
Change in carrying value of Series B preference shares			(8.4)
Other, net			(0.1)
Balance at beginning of year at Dec. 31, 2018				(202.4)
Accumulated net foreign currency translation (losses)
Net change in foreign currency translation				(27.8)
Balance at end of year at Mar. 31, 2019				(230.2)
Total common shareholders' equity at Mar. 31, 2019		$ 1,090.2	911.8	$ (230.2)		1,773.0
Accumulated net foreign currency translation (losses)
Non-controlling interests					$ 2.2	2.2
Total equity			$ 816.6			$ 1,775.2