Segment Information (Tables)

12 Months Ended

Dec. 31, 2019

Segment Reporting [Abstract]

Revenue and Income (Loss) Before Income Taxes for Each Segment

Revenue and income before income taxes for each segment were as follows:

	For the Years Ended December 31,
(in millions)	2019		2018			2017
Revenue:
Earned premiums
U.S. Operations	$	1,119.7	$	1,078.9		$	936.6
International Operations	609.6		652.5			635.8
Run-off Lines	0.2		0.3			(0.1		)
Total earned premiums	1,729.5		1,731.7			1,572.3
Net investment income
U.S. Operations	100.0		82.9			87.2
International Operations	44.2		32.9			32.7
Run-off Lines	5.7		8.1			9.3
Corporate and Other	1.2		9.2			10.8
Total net investment income	151.1		133.1			140.0
Fee and other income	9.1		9.0			22.5
Net realized investment gains (losses)	80.0		(72.0		)	39.3
Total revenue	$	1,969.7	$	1,801.8		$	1,774.1

	For the Years Ended December 31,
(in millions)	2019			2018			2017
(Loss) Income before income taxes
U.S. Operations	$	139.1		$	161.4		$	169.4
International Operations	(137.0		)	32.9			(86.7		)
Run-off Lines	(9.8		)	(9.3		)	(17.9		)
Total segment (loss) income before taxes	(7.7		)	185.0			64.8
Corporate and Other	(44.1		)	(45.4		)	(57.9		)
Net realized investment and other gain (losses)	80.0			(72.0		)	39.3
Foreign currency exchange gains	9.6			0.1			(6.3		)
Other corporate expenses	(37.6		)	—			—
Total income before income taxes	$	0.2		$	67.7		$	39.9

Schedule of Earned Premiums by Geographic Location

The table below presents earned premiums by geographic location. For this disclosure, we determine geographic location by the country of domicile of our subsidiaries that underwrite the business and not by the location of insureds or reinsureds from whom the business was generated.

	For the Years Ended December 31,
(in millions)	2019		2018		2017
United States	$	1,115.6	$	1,073.1	$	930.8
United Kingdom	391.5		455.8		489.3
Bermuda	80.7		85.4		92.1
Malta	85.0		61.0		11.1
All other jurisdictions	56.7		56.4		49.0
Total earned premiums	$	1,729.5	$	1,731.7	$	1,572.3

Identifiable Assets

The following table represents identifiable assets:

	December 31,
(in millions)	2019		2018
U.S. Operations	$	5,009.0	$	4,707.8
International Operations	5,002.4		3,984.7
Run-off Lines	356.9		444.8
Corporate and Other	146.2		420.9
Total	$	10,514.5	$	9,558.2

Schedule of Goodwill and Intangible Assets Net of Accumulated Amortization

The following table represents goodwill and intangible assets, net of accumulated amortization, as of December 31, 2019:

	Goodwill				Intangible Assets, Net of Accumulated Amortization
(in millions)	2019		2018		2019		2018
U.S. Operations	$	123.5	$	123.5	$	—	$	0.5
International Operations	37.9		53.5		91.8		93.0
Total	$	161.4	$	177.0	$	91.8	$	93.5