Derivative Financial Instruments Fair Value Gains and Losses on Derivative Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative [Line Items]
Net fair value gains on derivative financial instruments	$ 1,796	$ 904	$ 9,639	$ 1,699
Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Net fair value gains on derivative financial instruments	1,783	843	9,527	1,457
Interest Rate Swap [Member]
Derivative [Line Items]
Net fair value gains on derivative financial instruments	(12)	51	70	198
Foreign Exchange Contract [Member]
Derivative [Line Items]
Net fair value gains on derivative financial instruments	$ 25	$ 10	$ 42	$ 44