Restrictions on Cash, Securities, Bank Dividends, Loans or Advances (Details)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Regulated Operations [Abstract]
Reserve requirements with federal reserve	$ 113,341,000	$ 129,429,000
FHLB stock	19,777,000	15,070,000
FHLB required investment amount	7,471,000	$ 7,181,000
Amount transferable loans maximum	$ 133,162,000
Regulatory restrictions on payments of dividends, excess surplus ratio	10
Company borrowings	$ 0