Loans and Allowance for Loan Losses - Troubled Debt Restructurings That Are Not Performing (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020 USD ($)	Mar. 31, 2019	Dec. 31, 2019 USD ($)
Number of contracts	0	0
Nonperforming Financial Instruments [Member]
Number of contracts	6		5
Recorded investment, not performing	$ 1,474		$ 1,344
Taxi Medallion Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Number of contracts	5		4
Recorded investment, not performing	$ 1,195		$ 1,065
Commercial Business and Other Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Number of contracts	1		1
Recorded investment, not performing	$ 279		$ 279