Junior Subordinated Debentures - Junior Subordinated Debentures by Issuance (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Total liability, at par	$ 46,500	$ 46,500
Total liability, at carrying value	37,462	37,334
Metropolitan Statutory Trust 1
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Total liability, at par	35,000	35,000
RidgeStone Capital Trust I
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Total liability, at par	1,500	1,500
First Evanston Bancorp Trust I
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Total liability, at par	10,000	10,000
Junior Subordinated Debentures
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Discount	$ (9,038)	$ (9,166)
Junior Subordinated Debentures | Metropolitan Statutory Trust 1
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Stated Maturity	Mar. 17, 2034
Contractual Rate	3.63%	4.69%
Junior Subordinated Debentures | Metropolitan Statutory Trust 1 | Three-month LIBOR
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	2.79%	2.79%
Junior Subordinated Debentures | RidgeStone Capital Trust I
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Stated Maturity	Jun. 30, 2033
Contractual Rate	6.38%	6.38%
Junior Subordinated Debentures | RidgeStone Capital Trust I | Five-year LIBOR
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Interest Rate Spread, Description	Five-year LIBOR
Interest Rate Spread	3.50%	3.50%
Junior Subordinated Debentures | First Evanston Bancorp Trust I
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Stated Maturity	Mar. 15, 2035
Contractual Rate	2.52%	3.67%
Junior Subordinated Debentures | First Evanston Bancorp Trust I | Three-month LIBOR
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	1.78%	1.78%