Investment Securities - Schedule of Gains and Losses From Sales of Investment Securities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Investments Debt And Equity Securities [Abstract]
Gross Gains on Sales of Investment Securities		$ 38	$ 14,257	$ 7,701
Gross Losses on Sales of Investment Securities	$ (1,121)	(1,507)	(3,132)	(10,781)
Net Gains (Losses) on Sales of Investment Securities	$ (1,121)	$ (1,469)	$ 11,125	$ (3,080)