Debt Investment Securities at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Securities sold under agreements to repurchase	$ 65.5	$ 66.6
U.S. Treasury and Agency Obligations
Debt Instrument [Line Items]
Securities sold under agreements to repurchase	22.3	37.3
Collateralized Mortgage Backed Securities
Debt Instrument [Line Items]
Securities sold under agreements to repurchase	$ 43.2	$ 29.3

Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Balance Type:	credit
Period Type:	instant