Securities - Unrealized Gains (Losses) of Debt Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Total unrealized gains/(losses) on debt securities available-for-sale, Gross Unrealized Gains	$ 26,563	$ 33,478
Total unrealized gains/(losses) on debt securities available-for-sale, Gross Unrealized Losses	(2,888)	(90)
Total unrealized gains/(losses) on debt securities available-for-sale, Net Unrealized Gains/(Losses)	23,675	33,388
Income tax (expense) benefit, Gross Unrealized Gains	(5,668)	(7,128)
Income tax (expense) benefit, Gross Unrealized Losses	615	19
Income tax (expense) benefit, Net Unrealized Gains/(Losses)	(5,053)	(7,109)
Net Unrealized Gains/(Losses), Net of Tax Included in Accumulated Other Comprehensive Income/(Loss), Gross Unrealized Gains	20,895	26,350
Net Unrealized Gains/(Losses), Net of Tax Included in Accumulated Other Comprehensive Income/(Loss), Gross Unrealized Losses	(2,273)	(71)
Net Unrealized Gains/(Losses), Net of Tax Included in Accumulated Other Comprehensive Income/(Loss), Net Unrealized Gains/(Losses)	$ 18,622	$ 26,279