Borrowed Funds - Summary of Borrowed Funds (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Securities sold under agreements to repurchase	$ 121,079	$ 124,884
FHLB advances	785,000	590,000
Total borrowed funds	$ 906,079	$ 714,884

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.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant