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Fair Value - Rollforward of Level 3 assets and liabilities (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019
Contingent consideration liability |  |  |
Level 3 liabilities rollforward |  |  |
Balance at beginning of year |  | $ (7,998) | $ (66,665)
Total gains or (losses) (realized/unrealized) - included in earnings | [1] | (72) | (1,478)
Total gains or (losses) (realized/unrealized) - included in other comprehensive income |  | 0 | 0
Purchases, issuances, sales and settlements |  |  |
Purchases |  | 0 | 0
Issuances |  | 0 | (548)
Sales |  | 0 | 0
Settlements |  | 7,609 | 60,693
Transfers in and/or out of Level 3 |  | 0 | 0
Balance at end of year |  | (461) | (7,998)
Equity securities |  |  |
Level 3 assets rollforward |  |  |
Balance at beginning of year |  | 55,889 | 0
Total gains or (losses) (realized/unrealized) - included in earnings | [1] | 8,214 | (3,418)
Total gains or (losses) (realized/unrealized) - included in other comprehensive income |  | 0 | 0
Purchases, issuances, sales and settlements |  |  |
Purchases |  | 4,030 | 36,077
Issuances |  | 0 | 0
Sales |  | (26,118) | (27,982)
Settlements |  | 0 | 0
Transfers in and/or out of Level 3 |  | 0 | 51,212
Balance at end of year |  | 42,015 | 55,889
Available for sale | Structured securities |  |  |
Level 3 assets rollforward |  |  |
Balance at beginning of year | [2] | 5,216 | 313
Total gains or (losses) (realized/unrealized) - included in earnings | [1],[2] | 0 | 1,760
Total gains or (losses) (realized/unrealized) - included in other comprehensive income | [2] | (169) | 3
Purchases, issuances, sales and settlements |  |  |
Purchases | [2] | 0 | 0
Issuances | [2] | 0 | 0
Sales | [2] | 0 | (1,757)
Settlements | [2] | (1,413) | (552)
Transfers in and/or out of Level 3 | [2] | (208) | 5,449
Balance at end of year | [2] | 3,426 | 5,216
Available for sale | Corporate bonds |  |  |
Level 3 assets rollforward |  |  |
Balance at beginning of year |  | 8,851 | 8,141
Total gains or (losses) (realized/unrealized) - included in earnings | [1] | (5,865) | 2
Total gains or (losses) (realized/unrealized) - included in other comprehensive income |  | 397 | (267)
Purchases, issuances, sales and settlements |  |  |
Purchases |  | 0 | 881
Issuances |  | 0 | 0
Sales |  | 0 | 0
Settlements |  | (1,462) | (1,766)
Transfers in and/or out of Level 3 |  | (1,908) | 1,860
Balance at end of year |  | 13 | 8,851
Fair value option | Corporate bonds |  |  |
Level 3 assets rollforward |  |  |
Balance at beginning of year |  | 932 | 5,758
Total gains or (losses) (realized/unrealized) - included in earnings | [1] | (13) | (162)
Total gains or (losses) (realized/unrealized) - included in other comprehensive income |  | 0 | 0
Purchases, issuances, sales and settlements |  |  |
Purchases |  | 66 | 0
Issuances |  | 0 | 0
Sales |  | 0 | (28,583)
Settlements |  | 0 | 0
Transfers in and/or out of Level 3 |  | 0 | 23,919
Balance at end of year |  | 985 | 932
Fair value option | Other investments |  |  |
Level 3 assets rollforward |  |  |
Balance at beginning of year |  | 68,817 | 62,705
Total gains or (losses) (realized/unrealized) - included in earnings | [1] | (314) | (8,119)
Total gains or (losses) (realized/unrealized) - included in other comprehensive income |  | 0 | 0
Purchases, issuances, sales and settlements |  |  |
Purchases |  | 52,449 | 3,746
Issuances |  | 0 | 0
Sales |  | (56,833) | (20,495)
Settlements |  | 0 | (600)
Transfers in and/or out of Level 3 |  | 2,984 | 31,580
Balance at end of year |  | 67,103 | 68,817
Fair value option | Equity securities |  |  |
Level 3 assets rollforward |  |  |
Balance at beginning of year |  | 58,094 | 0
Total gains or (losses) (realized/unrealized) - included in earnings | [1] | 10,894 | 1,949
Total gains or (losses) (realized/unrealized) - included in other comprehensive income |  | 0 | 0
Purchases, issuances, sales and settlements |  |  |
Purchases |  | 0 | 0
Issuances |  | 0 | 0
Sales |  | 0 | 0
Settlements |  | 0 | 0
Transfers in and/or out of Level 3 |  | 0 | 56,145
Balance at end of year |  | $ 68,988 | $ 58,094
[1] | Gains or losses were included in net realized gains (losses).
[2] | Includes asset backed securities, mortgage backed securities and commercial mortgage backed securities

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