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Asset-Backed Securities Issued - Additional Information (Details)	3 Months Ended
	Mar. 31, 2019
Asset-backed securities issued | Contractual maturities of over five years
Debt Instrument [Line Items]
Contractual maturities of ABS (in years)	5 years

X

- Definition

Long Term Marketable Securities Maturities Term

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- 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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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: