Derivative Instruments (Details) - Maximum - Derivatives designated as hedges of fair value: - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Loss on Fair Value Hedge Ineffectiveness	$ 0.1	$ 0.1	$ 0.1	$ 0.1
Loans Receivable [Member] \| Derivative Financial Instruments, Assets [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	$ 0.1	$ 0.1	$ 0.1	$ 0.1

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=109977999&loc=d3e76258-113986

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- Definition

Amount of recognized loss from the hedging ineffectiveness of a fair value hedge.

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