SCHEDULE II CONDENSED FINANCIAL INFORMATION OF THE REGISTRANT - Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets
Total assets	$ 3,362.6	$ 3,659.2
Liabilities
Debt	192.7	23.8
Payable to subsidiary	4.0	11.6	$ 0.2
Total liabilities	644.4	298.4
White Mountains’s common shareholders’ equity	2,718.2	3,360.8
Non-controlling interests	(124.9)	(131.7)
Total liabilities and equity	3,362.6	3,659.2
Fair value investments	2,328.7	3,208.3	$ 2,547.3
White Mountains Insurance Group Ltd.
Assets
Cash	0.7	14.9
Fixed maturity investments, at fair value	0.0	869.6
Common equity securities, at fair value	335.6	641.8
Short-term investments, at amortized cost	28.0	57.2
Other long-term investments	0.0	(3.7)
Other assets	1.8	30.9
Investments in consolidated subsidiaries	2,533.2	1,914.8
Total assets	2,899.3	3,525.5
Liabilities
Payable to subsidiary	15.8	11.8
Other liabilities	25.9	21.2
Total liabilities	41.7	33.0
White Mountains’s common shareholders’ equity	2,843.1	3,492.5
Non-controlling interests	14.5	0.0
Total liabilities and equity	2,899.3	3,525.5
Sirius Group
Liabilities
Other liabilities	$ 17.3
Barclays | Forward Contracts | A
CONDENSED FINANCIAL INFORMATION OF THE REGISTRANT
Derivative, fair value, net		$ (3.7)