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Segment Information - Financial Information for White Mountain's Segments (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2021 | Mar. 31, 2020
Segment Reporting Information [Line Items] |  |
Earned insurance premiums | $ 111.0 | $ 5.4
Net investment income | 20.6 | 22.9
Net realized and unrealized investment (losses) gains | 1.1 | (186.7)
Net realized and unrealized investment (losses) gains from investment in MediaAlpha | (40.6) | (156.7)
Commission revenues | 61.9 | 55.1
Other revenues | 25.3 | 14.1
Total revenues | 178.2 | (59.2)
Loss and loss adjustment expenses | 66.0 |
Insurance and reinsurance acquisition expenses | 38.6 |
Cost of sales | 4.0 | 2.0
General and administrative expenses | 138.4 | 74.3
Loss on assets held for sale | 28.7 |
Broker commission expenses | 18.9 | 18.3
Change in fair value of contingent consideration earnout liabilities | 0.0 | (0.6)
Amortization of other intangible assets | 9.2 | 5.1
Interest expense | 13.1 | 6.0
Total expenses | 316.9 | 106.8
Pre-tax loss from continuing operations | (138.7) | (166.0)
Marketing Technology (MediaAlpha) |  |
Segment Reporting Information [Line Items] |  |
Net realized and unrealized investment (losses) gains from investment in MediaAlpha | (41.7) | 30.0
HG Global/ BAM |  |
Segment Reporting Information [Line Items] |  |
Earned insurance premiums | 6.4 | 5.4
Net investment income | 4.5 | 5.5
Net realized and unrealized investment (losses) gains | (17.9) | 6.1
Commission revenues | 0.0 | 0.0
Other revenues | 0.3 | 0.5
Total revenues | (6.7) | 17.5
Loss and loss adjustment expenses | 0.0 |
Insurance and reinsurance acquisition expenses | 1.9 |
Cost of sales | 0.0 | 0.0
General and administrative expenses | 16.4 | 14.7
Loss on assets held for sale | 0.0 |
Broker commission expenses | 0.0 | 0.0
Change in fair value of contingent consideration earnout liabilities | 0.0 | 0.0
Amortization of other intangible assets | 0.0 | 0.0
Interest expense | 0.0 | 0.0
Total expenses | 18.3 | 16.4
Pre-tax loss from continuing operations | (25.0) | 1.1
HG Global/ BAM | Marketing Technology (MediaAlpha) |  |
Segment Reporting Information [Line Items] |  |
Net realized and unrealized investment (losses) gains from investment in MediaAlpha | 0.0 | 0.0
Ark |  |
Segment Reporting Information [Line Items] |  |
Earned insurance premiums | 104.6 | 0.0
Net investment income | 0.8 | 0.0
Net realized and unrealized investment (losses) gains | 1.1 | 0.0
Commission revenues | 0.0 |
Other revenues | 2.6 | 0.0
Total revenues | 109.1 | 0.0
Loss and loss adjustment expenses | 66.0 | 0.0
Insurance and reinsurance acquisition expenses | 36.7 | 0.0
Cost of sales | 0.0 |
General and administrative expenses | 26.6 | 0.0
Loss on assets held for sale | 0.0 |
Broker commission expenses | 0.0 |
Change in fair value of contingent consideration earnout liabilities | 0.0 |
Amortization of other intangible assets | 0.0 |
Interest expense | 1.1 | 0.0
Total expenses | 141.6 | 0.0
Pre-tax loss from continuing operations | (32.5) |
Ark | General and administrative expenses, including underwriting expense |  |
Segment Reporting Information [Line Items] |  |
General and administrative expenses | 37.8 |
Ark | Marketing Technology (MediaAlpha) |  |
Segment Reporting Information [Line Items] |  |
Net realized and unrealized investment (losses) gains from investment in MediaAlpha | 0.0 |
NSM |  |
Segment Reporting Information [Line Items] |  |
Earned insurance premiums | 0.0 | 0.0
Net investment income | 0.0 | 0.0
Net realized and unrealized investment (losses) gains | 0.0 | 0.0
Commission revenues | 59.6 | 53.0
Other revenues | 15.2 | 12.0
Total revenues | 74.8 | 65.0
Loss and loss adjustment expenses | 0.0 |
Insurance and reinsurance acquisition expenses | 0.0 |
Cost of sales | 0.0 | 0.0
General and administrative expenses | 46.0 | 39.6
Loss on assets held for sale | 28.7 | 0.0
Broker commission expenses | 18.9 | 18.3
Change in fair value of contingent consideration earnout liabilities | 0.0 | (0.6)
Amortization of other intangible assets | 8.6 | 4.8
Interest expense | 5.9 | 4.3
Total expenses | 108.1 | 66.4
Pre-tax loss from continuing operations | (33.3) | (1.4)
NSM | Marketing Technology (MediaAlpha) |  |
Segment Reporting Information [Line Items] |  |
Net realized and unrealized investment (losses) gains from investment in MediaAlpha | 0.0 | 0.0
Kudu |  |
Segment Reporting Information [Line Items] |  |
Earned insurance premiums | 0.0 | 0.0
Net investment income | 8.2 | 7.3
Net realized and unrealized investment (losses) gains | 15.8 | (24.8)
Commission revenues | 0.0 | 0.0
Other revenues | 0.1 | 0.1
Total revenues | 24.1 | (17.4)
Loss and loss adjustment expenses | 0.0 |
Insurance and reinsurance acquisition expenses | 0.0 |
Cost of sales | 0.0 | 0.0
General and administrative expenses | 2.5 | 2.5
Loss on assets held for sale | 0.0 |
Broker commission expenses | 0.0 | 0.0
Change in fair value of contingent consideration earnout liabilities | 0.0 | 0.0
Amortization of other intangible assets | 0.1 | 0.1
Interest expense | 5.8 | 1.4
Total expenses | 8.4 | 4.0
Pre-tax loss from continuing operations | 15.7 | (21.4)
Kudu | Marketing Technology (MediaAlpha) |  |
Segment Reporting Information [Line Items] |  |
Net realized and unrealized investment (losses) gains from investment in MediaAlpha | 0.0 | 0.0
Other Operations |  |
Segment Reporting Information [Line Items] |  |
Earned insurance premiums | 0.0 | 0.0
Net investment income | 7.1 | 10.1
Net realized and unrealized investment (losses) gains | 2.1 | (168.0)
Commission revenues | 2.3 | 2.1
Other revenues | 7.1 | 1.5
Total revenues | (23.1) | (124.3)
Loss and loss adjustment expenses | 0.0 |
Insurance and reinsurance acquisition expenses | 0.0 |
Cost of sales | 4.0 | 2.0
General and administrative expenses | 35.7 | 17.5
Loss on assets held for sale | 0.0 |
Broker commission expenses | 0.0 | 0.0
Change in fair value of contingent consideration earnout liabilities | 0.0 | 0.0
Amortization of other intangible assets | 0.5 | 0.2
Interest expense | 0.3 | 0.3
Total expenses | 40.5 | 20.0
Pre-tax loss from continuing operations | (63.6) | (144.3)
Other Operations | Marketing Technology (MediaAlpha) |  |
Segment Reporting Information [Line Items] |  |
Net realized and unrealized investment (losses) gains from investment in MediaAlpha | $ (41.7) | $ 30.0

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