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Non-controlling Interests (Details) - USD ($) $ in Millions | Jun. 30, 2019 | Dec. 31, 2018
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Noncontrolling Interest [Line Items] |  |
Total non-controlling interests | $ (136.4) | $ (124.9)
Total Non-Controlling Excluding Reciprocals |  |
Noncontrolling Interest [Line Items] |  |
Total non-controlling interests | $ 32.4 | $ 45.7
HG Global |  |
Noncontrolling Interest [Line Items] |  |
Noncontrolling equity percentage | 3.10% | 3.10%
Total non-controlling interests | $ 14.9 | $ 14.5
NSM Holding Co LLC |  |
Noncontrolling Interest [Line Items] |  |
Noncontrolling equity percentage | 3.60% | 4.50%
Total non-controlling interests | $ 15.1 | $ 13.6
Other NSM |  |
Noncontrolling Interest [Line Items] |  |
Noncontrolling equity percentage | 13.40% | 13.40%
Total non-controlling interests | $ 0.1 | $ 0.3
Kudu Investment Management, LLC |  |
Noncontrolling Interest [Line Items] |  |
Noncontrolling equity percentage | 1.00% | 0.00%
Total non-controlling interests | $ 1.6 | $ 0.0
MediaAlpha |  |
Noncontrolling Interest [Line Items] |  |
Noncontrolling equity percentage | 0.00% | 39.00%
Total non-controlling interests | $ 0.0 | $ 16.2
Other Operations |  |
Noncontrolling Interest [Line Items] |  |
Total non-controlling interests | $ 0.7 | $ 1.1
Build America Mutual |  |
Noncontrolling Interest [Line Items] |  |
Noncontrolling equity percentage | 100.00% | 100.00%
Total non-controlling interests | $ (168.8) | $ (170.6)

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