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Derivatives - Derivatives Associated With Cash Flow Hedges (Details) - Cash Flow Hedge - Hedging Instruments And Hedged Items - USD ($) $ in Thousands | Jun. 30, 2020 | Dec. 31, 2019 | Mar. 31, 2017 | Mar. 31, 2016
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Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Notional |  |  | $ 650,000 |
Variability in cash flows related to debt instruments (primarily loans) |  |  |  | $ 250,000
Interest Rate Contract |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Variability in cash flows related to debt instruments (primarily loans) | $ 700,000 | $ 900,000 |  |
Interest Rate Swap |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Notional | 700,000 | 900,000 |  |
Assets | 29 |  |  |
Liabilities | $ 48 | $ 241 |  |

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