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SCHEDULE II CONDENSED FINANCIAL INFORMATION OF THE REGISTRANT - Statement of Cash Flows (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
CONDENSED FINANCIAL INFORMATION OF THE REGISTRANT |  |  |
Net income (loss) attributable to White Mountains’s common shareholders | $ (275.4) | $ 708.7 | $ 414.5
Adjustments to reconcile net income to net cash used for operations: |  |  |
Net change in other assets and liabilities, net | 24.2 | 30.9 | 20.4
Net cash provided from (used for) operations | 38.6 | (60.6) | (120.5)
Cash flows from investing activities: |  |  |
Net change in short-term investments | 54.3 | 58.7 | 21.9
Net cash provided from (used for) investing activities | (208.3) | 64.6 | (59.9)
Cash flows from financing activities: |  |  |
Repurchases and retirement of common shares | (100.1) | (78.5) | 0.0
Dividends paid on common shares | (3.1) | (3.2) | (3.2)
Net cash provided from (used for) financing activities | 217.6 | 49.0 | 230.5
Net decrease in cash during the year | 48.1 | 50.2 | 50.7
Cash balance at beginning of year | 211.2 | 161.0 | 110.3
Cash balance at end of year | 259.3 | 211.2 | 161.0
Amortization of restricted share awards | 14.7 | 16.6 | 10.5
Net change in (receivables) payables to subsidiaries | 6.5 | 4.8 | 6.6
White Mountains Insurance Group Ltd. |  |  |
CONDENSED FINANCIAL INFORMATION OF THE REGISTRANT |  |  |
Net income (loss) attributable to White Mountains’s common shareholders | (275.4) | 708.7 | 414.5
Adjustments to reconcile net income to net cash used for operations: |  |  |
Net realized and unrealized investment (gains) losses from MediaAlpha | 0.1 | 10.1 | (61.0)
Undistributed earnings from subsidiaries | 257.4 | (782.0) | (398.5)
Net (gain) loss from sale of discontinued operations, net of tax | (18.7) | 2.3 | (0.8)
Other non-cash reconciling items, primarily amortization of restricted shares and option awards | 14.1 | 19.0 | 20.0
Net change in other assets and liabilities, net | (5.7) | (2.6) | 3.0
Net cash provided from (used for) operations | (28.2) | (44.5) | (22.8)
Cash flows from investing activities: |  |  |
Net change in short-term investments | 17.7 | (127.4) | (37.6)
Purchases of investment securities | 0.0 | (6.7) | (14.8)
Sales and maturities of investment securities | 0.0 | 189.7 | 207.9
Purchases of investment securities from subsidiaries | (26.4) | 0.0 | 0.0
Sales of investment securities to subsidiaries | 36.4 | 0.0 | 0.0
Issuance of debt (to) from subsidiaries | 94.0 | (44.5) | (83.5)
Repayment of debt to (from) subsidiaries | 0.0 | 92.6 | 5.0
Net distributions from (contributions to) subsidiaries | 17.0 | 29.1 | (46.1)
Net cash provided from (used for) investing activities | 138.7 | 132.8 | 30.9
Cash flows from financing activities: |  |  |
Repurchases and retirement of common shares | (100.1) | (78.5) | 0.0
Dividends paid on common shares | (3.1) | (3.2) | (3.2)
Payments of restricted shares withholding taxes | (7.4) | (6.6) | (4.9)
Net cash provided from (used for) financing activities | (110.6) | (88.3) | (8.1)
Net decrease in cash during the year | (0.1) | 0.0 | 0.0
Cash balance at beginning of year | 0.7 | 0.7 | 0.7
Cash balance at end of year | 0.6 | 0.7 | 0.7
Bridge Holdings, Ltd. |  |  |
Cash flows from financing activities: |  |  |
Excess of intercompany debt | 12.6 |  |
Bridge Holdings, Ltd. | White Mountains Insurance Group Ltd. |  |  |
Cash flows from investing activities: |  |  |
Repayment of debt to (from) subsidiaries | 200.0 |  |
Net distributions from (contributions to) subsidiaries | 18.0 |  |
Cash flows from financing activities: |  |  |
Proceeds from Contributions from Parent |  |  | (70.5)
Bridge Holdings, Ltd. | White Mountains Insurance Group Ltd. | Short-term investments |  |  |
Cash flows from investing activities: |  |  |
Net distributions from (contributions to) subsidiaries | 17.9 |  |
Bridge Holdings, Ltd. | White Mountains Insurance Group Ltd. | Cash |  |  |
Cash flows from investing activities: |  |  |
Net distributions from (contributions to) subsidiaries | 0.1 |  |
HG Global | White Mountains Insurance Group Ltd. |  |  |
Cash flows from financing activities: |  |  |
Proceeds from Contributions from Affiliates |  | 22.3 | 1.9
White Mountains Adams, Inc. | White Mountains Insurance Group Ltd. |  |  |
Cash flows from investing activities: |  |  |
Net distributions from (contributions to) subsidiaries | (42.7) |  |
White Mountains Adams, Inc. | White Mountains Insurance Group Ltd. | Short-term investments |  |  |
Cash flows from investing activities: |  |  |
Net distributions from (contributions to) subsidiaries | (37.1) |  |
White Mountains Adams, Inc. | White Mountains Insurance Group Ltd. | Cash |  |  |
Cash flows from investing activities: |  |  |
Net distributions from (contributions to) subsidiaries | (5.6) |  |
White Mountains Investments Bermuda | White Mountains Insurance Group Ltd. |  |  |
Cash flows from financing activities: |  |  |
Proceeds from Contributions from Parent |  |  | (2.0)
Proceeds from Contributions from Affiliates |  |  | 24.4
PSC Holdings, Ltd | White Mountains Insurance Group Ltd. |  |  |
Cash flows from financing activities: |  |  |
Proceeds from Contributions from Affiliates |  | 6.8 |
Non-cash reconciling item | Guilford Holdings, Inc. |  |  |
Cash flows from financing activities: |  |  |
Transfer to investments |  | 169.6 |
Short-term investments | White Mountains Insurance Group Ltd. |  |  |
Cash flows from financing activities: |  |  |
Transfer to investments |  | 169.6 |
WM Lincoln |  |  |
Cash flows from financing activities: |  |  |
Carrying value of stock transferred | 212.6 |  |
White Mountains Investments Bermuda | White Mountains Insurance Group Ltd. |  |  |
Cash flows from financing activities: |  |  |
Proceeds from Contributions from Affiliates | (19.7) |  |
White Mountains Investments Bermuda | White Mountains Insurance Group Ltd. | Short-term investments |  |  |
Cash flows from financing activities: |  |  |
Proceeds from Contributions from Affiliates | (19.1) |  |
White Mountains Investments Bermuda | White Mountains Insurance Group Ltd. | Cash |  |  |
Cash flows from financing activities: |  |  |
Proceeds from Contributions from Affiliates | (0.6) |  |
Swedish Tax Authority | Sirius Group |  |  |
Cash flows from financing activities: |  |  |
Loss contingency accrual, period increase (decrease) | 18.7 | (2.3) | 0.8
Swedish Tax Authority | Sirius Group | White Mountains Insurance Group Ltd. |  |  |
Cash flows from financing activities: |  |  |
Loss contingency accrual, period increase (decrease) | $ 18.7 | $ (2.3) | $ 0.8

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