Securities Sold Under Agreements to Repurchase - Textual (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Banking and Thrift [Abstract]
Repurchase agreements	$ 99.6	$ 122.0

Amount, before effects of master netting arrangements, of funds outstanding borrowed in the form of a financial asset repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same financial asset at a date certain for a specified price. Includes repurchase-to-maturity transactions and liabilities not subject to a master netting arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 7
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=109249958&loc=SL34722452-111729

Name:	us-gaap_FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant