Non-controlling Interest (Tables)

9 Months Ended

Sep. 30, 2016

Noncontrolling Interest [Abstract]

Noncontrolling Interest Disclosure

The following table details the balance of non-controlling interests included in White Mountains’s total equity and the related percentage of each consolidated entity’s total equity owned by non-controlling shareholders as of September 30, 2016 and December 31, 2015:

	September 30, 2016					December 31, 2015
$ in millions	Non-controlling Percentage		Non-controlling Equity			Non-controlling Percentage		Non-controlling Equity
OneBeacon Ltd.	23.9	%	$	247.0		24.5	%	$	245.6
SIG Preference Shares	—		—			100.0		250.0
Other, excluding mutuals and reciprocals
HG Global	3.1		16.9			3.1		17.1
MediaAlpha	40.0		12.5			40.0		14.4
Tranzact	—		—			36.8		79.4
Wobi	3.3		.5			3.9		.6
Dewar	18.8		3.7			19.0		3.7
Buzzmove	29.1		3.3			—		—
Total other, excluding mutuals and reciprocals			36.9					115.2
Mutuals and reciprocals
BAM	100.0		(138.9		)	100.0		(140.0		)
SSIE	100.0		4.2			100.0		(16.0		)
Total mutuals and reciprocals			(134.7		)			(156.0		)
Total non-controlling interests			$	149.2				$	454.8