Fair Value - Changes in Fair Value Levels and in Level 3 Liabilities (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Fair value
Amount of transfers between hierarchy levels	$ 0
Visa derivative | Funding Swap (Visa Derivative)
Changes in Level 3 liabilities measured at fair value on a recurring basis
Balance	(4,233,000)	$ (2,607,000)
Total net gains included in other noninterest income	6,000	5,000
Settlements	1,028,000	763,000
Balance	(3,199,000)	(1,839,000)
Total net gains included in net income attributable to the change in unrealized gains or losses related to liabilities still held as of March 31,	$ 6,000	$ 5,000