Non-controlling Interest

9 Months Ended

Sep. 30, 2015

Noncontrolling Interest [Abstract]

Noncontrolling Interest Disclosure [Text Block]

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, 2015 and December 31, 2014:

	September 30, 2015					December 31, 2014
$ in millions	Non-controlling Percentage		Non-controlling Equity			Non-controlling Percentage		Non-controlling Equity
OneBeacon Ltd.	24.7	%	$	246.9		24.7	%	$	258.4
SIG Preference Shares	100.0		250.0			100.0		250.0
Other, excluding mutuals and reciprocals
HG Global	3.1		17.3			3.1		17.9
MediaAlpha	40.0		15.1			40.0		22.6
Tranzact	36.8		75.6			36.8		88.2
Wobi	4.7		1.8			36.7		5.4
Dewar	32.2		3.5			18.0		3.4
Prospector Offshore Fund	—		—			23.4		31.1
Total other, excluding mutuals and reciprocals			113.3					168.6
Mutuals and reciprocals
BAM	100.0		(134.2		)	100.0		(121.9		)
SSIE	100.0		(15.2		)	100.0		(12.4		)
Total non-controlling interests			$	460.8				$	542.7