Fair Value - Changes in Fair Value Levels and in Level 3 Liabilities (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Fair value
Amount of transfers between hierarchy levels	$ 0		$ 0
Visa derivative | Funding Swap (Visa Derivative)
Changes in Level 3 liabilities measured at fair value on a recurring basis
Balance	(3,199,000)	$ (1,839,000)	(4,233,000)	$ (2,607,000)
Total net gains (losses) included in other noninterest income	103,000	(247,000)	109,000	(242,000)
Settlements	1,001,000	907,000	2,029,000	1,670,000
Balance	(2,095,000)	(1,179,000)	(2,095,000)	(1,179,000)
Total net gains (losses) included in net income attributable to the change in unrealized gains or losses related to liabilities still held as of June 30,	$ 103,000	$ (247,000)	$ 109,000	$ (242,000)