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v3.19.3.a.u2

Statutory Capital and Surplus (Details) - USD ($) | 1 Months Ended | 12 Months Ended
--- | --- | ---
Jan. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Statutory Accounting Practices [Line Items] |  |  |  |  |
Repayments of debt, principal |  |  | $ 22,900,000 | $ 15,400,000 | $ 365,000,000.0
Other long-term investments |  | $ 856,000,000 | 856,000,000 |  |
Kudu |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Proceeds from borrowings |  | 57,000,000.0 |  |  |
Distributions made |  | 53,700,000 |  |  |
BAM |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Accrued interest on surplus notes |  | 162,700,000 | 162,700,000 | 143,700,000 |
Other Operations |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Unrestricted cash |  | 602,600,000 | 602,600,000 |  |
Other long-term investments |  | 202,300,000 | 202,300,000 |  |
HG Re | HG Global-BAM |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Statutory capital and surplus |  | 745,400,000 | 745,400,000 |  |
Surplus required |  | 1 | 1 |  |
Cash outside of collateral trusts |  | 3,000,000.0 | 3,000,000.0 |  |
Collateral held in supplement trust |  | 786,700,000 | 786,700,000 |  |
Cash and investments outside of collateral trusts |  | 6,300,000 | 6,300,000 |  |
Accrued interest held in Supplemental Trust |  | 111,200,000 | 111,200,000 |  |
BAM | HG Global-BAM |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Statutory capital and surplus |  | 402,400,000 | 402,400,000 |  |
Statutory net income (loss) |  |  | (38,300,000) | (34,600,000) | (25,400,000)
Surplus required |  | 66,000,000.0 | $ 66,000,000.0 |  |
HG Global |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Percent over a target trust balance |  |  | 102.00% |  |
Supplement Trust target |  | 603,000,000.0 | $ 603,000,000.0 |  |
HG Global | HG Global-BAM |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Preferred stock, value |  | $ 619,000,000.0 | $ 619,000,000.0 |  |
Ownership interest (as a percent) |  | 96.90% | 96.90% |  |
Preferred stock dividend rate |  |  | 6.00% |  |
White Mountains | Kudu |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Distributions made |  | $ 53,300,000 |  |  |
NSM Insurance HoldCo, LLC | NSM Insurance HoldCo, LLC |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Cash |  | 33,400,000 | $ 33,400,000 |  |
Kudu |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Cash and short-term investments |  | 5,900,000 | 5,900,000 |  |
Surplus Note | BAM |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Special cash payment |  |  | 32,000,000.0 | 23,000,000.0 | 5,000,000.0
Accrued interest on surplus notes |  | 8,000,000.0 | 8,000,000.0 | 4,600,000 | $ 900,000
Preferred stocks | HG Global |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Dividends payable |  | 2,000,000.0 | 2,000,000.0 |  |
Preferred stocks | HG Global | HG Global-BAM |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Dividends payable |  | 341,700,000 | 341,700,000 |  |
Preferred stocks | White Mountains | HG Global | HG Global-BAM |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Dividends payable |  | 330,200,000 | 330,200,000 |  |
Common Equities | Other Operations |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Distributions made |  |  |  | 3,200,000 |
Common equity securities |  | 683,900,000 | 683,900,000 |  |
Surplus Note | BAM |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Accrued interest held in Supplemental Trust |  | 300,000 | 300,000 | 700,000 |
Special cash payment |  |  | 32,000,000.0 | 23,000,000.0 |
Accrued interest on surplus notes |  | $ 8,000,000.0 | 8,000,000.0 | 4,600,000 |
Repayments of debt, principal |  |  | $ 23,700,000 | $ 17,700,000 |
Subsequent Event | BAM |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Accrued interest on surplus notes | $ 146,500,000 |  |  |  |
Subsequent Event | Surplus Note | BAM |  |  |  |  |
Statutory Accounting Practices [Line Items] |  |  |  |  |
Accrued interest held in Supplemental Trust | 900,000 |  |  |  |
Special cash payment | 65,000,000.0 |  |  |  |
Accrued interest on surplus notes | 16,200,000 |  |  |  |
Repayments of debt, principal | $ 47,900,000 |  |  |  |

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