Restrictions on Cash, Securities, Bank Dividends, Loans or Advances (Details)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Regulated Operations [Abstract]
Reserve requirements with federal reserve	$ 187,839,000	$ 113,341,000
FHLB stock	31,092,000	19,777,000
FHLB required investment amount	$ 31,092,000	$ 7,471,000
Regulatory restrictions on payments of dividends, excess surplus ratio	10
Amount transferable loans maximum	$ 138,862,000
Company borrowings	$ 0