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SCHEDULE II CONDENSED FINANCIAL INFORMATION OF THE REGISTRANT - Statement of Cash Flows (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Sep. 30, 2018 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
CONDENSED FINANCIAL INFORMATION OF THE REGISTRANT |  |  |  |  |  |  |  |  |  |  |  |
Net income (loss) attributable to White Mountains’s common shareholders | $ 60.9 | $ 48.7 | $ 20.5 | $ 284.4 | $ (137.5) | $ 40.8 | $ 3.5 | $ (48.0) |  | $ 414.5 | $ (141.2) | $ 627.2
Charges (credits) to reconcile net income to net cash provided from (used for) operations: |  |  |  |  |  |  |  |  |  |  |  |
Net realized and unrealized investment (gains) losses |  |  |  |  |  |  |  |  |  | (433.2) | 108.3 | (133.3)
Net income from discontinued operations, net of tax | 0.8 | $ (0.9) | $ 0.0 | (0.7) | 0.0 | $ 17.3 | $ 0.0 | (0.1) |  | 0.0 | 0.0 | (20.5)
Net change in other assets and liabilities, net |  |  |  |  |  |  |  |  |  | 18.7 | (27.1) | (20.8)
Net cash (used for) provided from operations |  |  |  |  |  |  |  |  |  | (120.5) | (31.1) | 94.6
Cash flows from investing activities: |  |  |  |  |  |  |  |  |  |  |  |
Net decrease in short-term investments |  |  |  |  |  |  |  |  |  | 21.9 | (39.0) | (1.7)
Net cash (used for) provided from investing activities |  |  |  |  |  |  |  |  |  | (59.9) | 459.2 | 718.5
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Draw down of debt and revolving line of credit |  |  |  |  |  |  |  |  |  | 206.4 | 84.1 | 376.0
Repayment of debt and revolving line of credit |  |  |  |  |  |  |  |  |  | (22.9) | (15.4) | (365.0)
Repurchases and retirement of common shares |  |  |  |  |  |  |  |  |  | 0.0 | (511.9) | (714.6)
Dividends paid on common shares |  |  |  |  |  |  |  |  |  | (3.2) | (3.8) | (4.6)
Net cash provided from (used for) financing activities |  |  |  |  |  |  |  |  |  | 230.5 | (414.3) | (699.0)
Net change in cash during the period - continuing operations |  |  |  |  |  |  |  |  |  |  |  | (0.9)
Cash balance at beginning of year |  |  |  | 110.3 |  |  |  | 97.1 | $ 97.1 | 110.3 | 97.1 | 80.2
Cash balance at end of year | 161.0 |  |  |  | 110.3 |  |  |  |  | 161.0 | 110.3 | 97.1
Interest paid |  |  |  |  |  |  |  |  |  | (16.3) | (8.8) | (1.4)
White Mountains’s common shareholders’ equity | 3,144.7 |  |  |  | 2,718.2 |  |  |  |  | 3,144.7 | 2,718.2 |
Amortization of restricted share and option awards |  |  |  |  |  |  |  |  |  | 10.5 | 13.0 | 14.8
Payable to subsidiary | (6.6) |  |  |  | (4.0) |  |  |  |  | (6.6) | (4.0) | (11.6)
Lone Tree Holdings Ltd. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
White Mountains’s common shareholders’ equity |  |  |  |  |  |  |  |  |  |  |  | 2,810.4
Other liabilities |  |  |  |  |  |  |  |  |  |  |  | 14.1
Investments in consolidated subsidiaries |  |  |  |  |  |  |  |  |  |  |  | 964.4
Short-term investments, at amortized cost |  |  |  |  |  |  |  |  |  |  |  | 13.0
White Mountains Insurance Group Ltd. |  |  |  |  |  |  |  |  |  |  |  |
CONDENSED FINANCIAL INFORMATION OF THE REGISTRANT |  |  |  |  |  |  |  |  |  |  |  |
Net income (loss) attributable to White Mountains’s common shareholders |  |  |  |  |  |  |  |  |  | 414.5 | (141.2) | 627.2
Charges (credits) to reconcile net income to net cash provided from (used for) operations: |  |  |  |  |  |  |  |  |  |  |  |
Net realized and unrealized investment (gains) losses |  |  |  |  |  |  |  |  |  | (61.0) | 57.8 | (18.5)
Undistributed earnings from subsidiaries |  |  |  |  |  |  |  |  |  | (398.5) | 27.4 | (701.0)
Net income from discontinued operations, net of tax |  |  |  |  |  |  |  |  |  | (0.8) | 17.2 | 0.0
Other non-cash reconciling items, primarily amortization of restricted share and option awards (4) |  |  |  |  |  |  |  |  |  | 20.0 | 34.6 | 31.1
Accumulated earnings distributed from subsidiary in cash |  |  |  |  |  |  |  |  |  | 0.0 | 0.0 | 1,256.7
Net change in other assets and liabilities, net |  |  |  |  |  |  |  |  |  | 3.0 | 16.7 | (4.9)
Net cash (used for) provided from operations |  |  |  |  |  |  |  |  |  | (22.8) | 12.5 | 1,190.6
Cash flows from investing activities: |  |  |  |  |  |  |  |  |  |  |  |
Net decrease in short-term investments |  |  |  |  |  |  |  |  |  | (37.6) | 134.0 | (24.7)
Payments to Acquire Investments |  |  |  |  |  |  |  |  |  | (14.8) | (321.2) | (474.7)
Proceeds from Sale and Maturity of Debt and Equity Securities, FV-NI, Held-for-investment |  |  |  |  |  |  |  |  |  | 207.9 | 967.6 | 367.1
Issuance of debt (to) from subsidiaries |  |  |  |  |  |  |  |  |  | (83.5) | (55.2) | 382.0
Repayment of debt (to) from subsidiaries |  |  |  |  |  |  |  |  |  | 5.0 | 31.0 | 0.0
Payments to acquire interest in subsidiary |  |  |  |  |  |  |  |  |  | 46.1 | 258.2 | 700.0
Net cash (used for) provided from investing activities |  |  |  |  |  |  |  |  |  | 30.9 | 498.0 | (450.3)
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Draw down of debt and revolving line of credit |  |  |  |  |  |  |  |  |  | 0.0 | 0.0 | 350.0
Repayment of debt and revolving line of credit |  |  |  |  |  |  |  |  |  | 0.0 | 0.0 | (350.0)
Repurchases and retirement of common shares |  |  |  |  |  |  |  |  |  | 0.0 | (510.9) | (714.6)
Dividends paid on common shares |  |  |  |  |  |  |  |  |  | (3.2) | (3.8) | (4.6)
Payments of restricted shares withholding taxes |  |  |  |  |  |  |  |  |  | (4.9) | (10.0) | (9.3)
Net cash provided from (used for) financing activities |  |  |  |  |  |  |  |  |  | (8.1) | (524.7) | (728.5)
Net change in cash during the period - continuing operations |  |  |  |  |  |  |  |  |  | 0.0 | (14.2) | 11.8
Cash balance at beginning of year |  |  |  | $ 0.7 |  |  |  | $ 14.9 | 14.9 | 0.7 | 14.9 | 3.1
Cash balance at end of year | 0.7 |  |  |  | 0.7 |  |  |  |  | 0.7 | 0.7 | 14.9
Interest paid |  |  |  |  |  |  |  |  |  | 0.0 | 0.0 | (0.6)
White Mountains’s common shareholders’ equity | 3,261.5 |  |  |  | 2,843.1 |  |  |  |  | 3,261.5 | 2,843.1 |
Other liabilities | 34.7 |  |  |  | 25.9 |  |  |  |  | 34.7 | 25.9 |
Investments in consolidated subsidiaries | 2,969.0 |  |  |  | 2,533.2 |  |  |  |  | 2,969.0 | 2,533.2 |
Short-term investments, at amortized cost | 66.2 |  |  |  | 28.0 |  |  |  |  | 66.2 | 28.0 |
Payable to subsidiary | $ 69.3 |  |  |  | $ (15.8) |  |  |  |  | 69.3 | (15.8) |
Transfer from investments |  |  |  |  |  |  |  |  |  |  |  | 1,238.9
Lone Tree Holdings Ltd. | White Mountains Insurance Group Ltd. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Net change in due to affiliates |  |  |  |  |  |  |  |  |  |  |  | 1,256.7
Proceeds from divestiture of businesses |  |  |  |  |  |  |  |  |  |  |  | 1,037.6
Bridge Holdings, Ltd. | White Mountains Insurance Group Ltd. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from investing activities: |  |  |  |  |  |  |  |  |  |  |  |
Payments to acquire interest in subsidiary |  |  |  |  |  |  |  |  |  |  | (255.3) |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer to investments |  |  |  |  |  |  |  |  |  | 70.5 | (22.7) |
White Mountains Investment, Ltd. | White Mountains Insurance Group Ltd. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from investing activities: |  |  |  |  |  |  |  |  |  |  |  |
Payments to acquire interest in subsidiary |  |  |  |  |  |  |  |  |  |  | (2.9) |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer to investments |  |  |  |  |  |  |  |  |  | 2.0 |  |
Transfer from investments |  |  |  |  |  |  |  |  |  | 24.4 |  |
HG Global | White Mountains Insurance Group Ltd. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer from investments |  |  |  |  |  |  |  |  |  | 1.9 |  |
Intercompany balances | Lone Tree Holdings Ltd. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Other liabilities |  |  |  |  |  |  |  |  |  |  |  | 1,863.1
Non-cash reconciling item | White Mountains Insurance Group Ltd. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer to investments |  |  |  |  |  |  |  |  |  |  |  | $ (94.2)
Non-cash reconciling item | Guilford Holdings, Inc. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer to investments |  |  |  |  |  |  |  |  |  |  | (349.5) |
Noncash Total | White Mountains Insurance Group Ltd. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer to investments |  |  |  |  |  |  |  |  |  |  | 603.9 |
Transfer from investments |  |  |  |  |  |  |  |  |  |  | 1,065.4 |
Fixed maturity investments | White Mountains Insurance Group Ltd. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer to investments |  |  |  |  |  |  |  |  |  |  | 170.5 |
Transfer from investments |  |  |  |  |  |  |  |  |  |  | 373.4 |
Fixed maturity investments | Guilford Holdings, Inc. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer from investments |  |  |  |  |  |  |  |  |  |  | 170.4 |
Common equity securities | White Mountains Insurance Group Ltd. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer to investments |  |  |  |  |  |  |  |  |  |  | 148.8 |
Transfer from investments |  |  |  |  |  |  |  |  |  |  | 490.1 |
Other long-term investments | White Mountains Insurance Group Ltd. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer to investments |  |  |  |  |  |  |  |  |  |  | 22.7 |
Transfer from investments |  |  |  |  |  |  |  |  |  |  | 22.7 |
Short-term investments | White Mountains Insurance Group Ltd. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer to investments |  |  |  |  |  |  |  |  |  |  | (284.6) |
Transfer from investments |  |  |  |  |  |  |  |  |  |  | 179.2 |
Short-term investments | Guilford Holdings, Inc. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer from investments |  |  |  |  |  |  |  |  |  |  | 179.2 |
Bridge Holdings, Ltd. | Guilford Holdings, Inc. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer to investments |  |  |  |  |  |  |  |  |  |  | (350.0) |
Bridge Holdings, Ltd. | White Mountains Investment, Ltd. |  |  |  |  |  |  |  |  |  |  |  |
Cash flows from financing activities: |  |  |  |  |  |  |  |  |  |  |  |
Transfer to investments |  |  |  |  |  |  |  |  |  |  | $ (1.0) |
Swedish Tax Authority | Sirius Group | Sirius Group |  |  |  |  |  |  |  |  |  |  |  |
Charges (credits) to reconcile net income to net cash provided from (used for) operations: |  |  |  |  |  |  |  |  |  |  |  |
Net income from discontinued operations, net of tax |  |  |  |  |  |  |  |  | $ 17.3 | $ (0.8) |  |

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