Securities Sold Under Agreements to Repurchase (Details Textual) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	$ 489,620,000	$ 396,151,000
Securities Pledged for Repurchase Agreements	$ 607,780,000	$ 511,294,000

Amount, before 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 elected not to be offset.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant