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Derivative Financial Instruments (Narrative) (Details) - FFL [Member] - Swap [Member] - USD ($) $ in Millions | Feb. 13, 2014 | Mar. 31, 2019 | Dec. 31, 2018 | Jul. 31, 2018 | Jan. 31, 2018
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Debt Instrument [Line Items] |  |  |  |  |
Swap agreement collateral |  | $ 31 |  |  |
Notional amount |  | $ 106 | $ 100 |  |
Term of swap agreement | 1 year |  |  |  |
LIBOR [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Basis spread on variable rate | 1.28% |  |  | 1.05% | 1.20%

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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition The percentage points added to the reference rate to compute the variable rate on the interest rate derivative. + References No definition available. + Details
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- Definition Amount of right to receive securities collateral under master netting arrangements that have not been offset against derivative liabilities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226016-175313 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 + Details
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- Definition Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Details
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- Details
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- Details
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