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Fair Value of Financial Instruments (Level 3 Liabilities) (Details) - Level 3 - Recurring basis - USD ($) $ in Thousands | 3 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2021 | Mar. 31, 2021 | Mar. 31, 2020
Agreements with Non-mark-to-market Collateral Provisions |  |  |
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |  |
Balance at beginning of period | $ 1,159,213 |  |
Issuances | 0 |  |
Payment of principal | (117,695) |  |
Changes in unrealized losses | (235) |  |
Balance at end of period | 1,159,213 | $ 1,041,283 |
Agreements with Mark-to-market Collateral Provisions |  |  |
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |  |
Balance at beginning of period | 1,124,162 |  |
Issuances | 91,997 |  |
Payment of principal | (236,618) |  |
Changes in unrealized losses | 0 |  |
Balance at end of period | $ 1,124,162 |  | $ 979,541

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- Definition Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Principal Paydowns + References No definition available. + Details
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- Definition Amount of unrealized gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3) and still held. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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