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Borrowings - Short Term Borrowings (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017
Short-term borrowings: |  |
Short-Term | $ 0 | $ 0
Maximum outstanding at any month end | 300,000,000 | 300,000,000
Secured Borrowing Facility |  |
Short-term borrowings: |  |
Short-Term | $ 0 | $ 0
Weighted Average Interest Rate | 0.00% | 0.00%
Average Balance | $ 52,603,000 | $ 81,370,000
Weighted Average Interest Rate | 8.91% | 6.09%
Commercial Paper | Secured Borrowing Facility |  |
Short-term borrowings: |  |
Short-Term | $ 0 | $ 0

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