Deposits - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Banking and Thrift [Abstract]
Aggregate amount of certificates of deposit exceeding threshold amount	$ 885.3	$ 640.1

Amount of time deposit liabilities, including certificates of deposit, in denominations of $100,000 or more.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher SEC
-Name Industry Guide
-Number 3
-Section V
-Paragraph D-E