Investment Securities (Available-for-sale Securities Gross Realized Gains and Losses) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Gross gains and gross losses realized from sales of available-for-sale securities:
Gross gains realized	$ 2	$ 97	$ 386	$ 157
Gross losses realized	0	0	3	87
Net gain realized	$ 2	$ 97	$ 383	$ 70

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

No definition available.

Name:	us-gaap_AvailableforsaleSecuritiesGrossRealizedGainLossExcludingOtherThanTemporaryImpairments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration