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Related Party Transaction (Details) - USD ($) |  | 12 Months Ended |
--- | --- | --- | ---
Jul. 01, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | Mar. 05, 2019
Related Party Transaction [Line Items] |  |  |  |
Borrowed federal funds |  | $ 50,000,000.0 | $ 50,000,000.0 |
Sale of stock, consideration received on transaction | $ 90,000,000 |  |  |
Sale of stock, percentage of ownership | 4.70% |  |  |
Common Stock Issued | Private Placement |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Sale of stock, number of shares Issued in transaction (in shares) | 577,254 |  |  |
Sale of stock, consideration received on transaction | $ 90,000,000.0 |  |  |
Convertible Senior Notes Due 2027 | Convertible Debt |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Aggregate amount | $ 310,000,000.0 |  |  |
Discovery Benefits, Inc. |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Ownership percentage by noncontrolling interest |  | 4.90% |  | 4.90%

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