Acquisitions - Additional Information (Details) - USD ($)			3 Months Ended		12 Months Ended
	May 15, 2019	Apr. 30, 2019	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill			$ 148,353,000	$ 128,177,000	$ 148,353,000	$ 128,177,000
Oak Park River Forest Bankshares, Inc.
Business Acquisition [Line Items]
Business acquisition date of agreement			Apr. 30, 2019
Right to receive common stock upon conversion		7.9321
Consideration paid in cash	$ 4,200,000	$ 6,163,000
Common stock outstanding value per share		$ 33.375
Common stock issued price per share		$ 20.02
Issuance of common shares		1,464,558
Value of common stock consideration		$ 29,300,000
Options to acquire common stock shares		35,870
Option to acquire common stock value		$ 4,200,000
Total merger consideration		35,483,000
Stock issuance costs		585,000
Goodwill		$ 20,176,000
Oak Park River Forest Bankshares, Inc. | Non-interest Expense
Business Acquisition [Line Items]
Acquisition advisory expenses				18,000	2,300,000
Core system conversion expenses				$ 0	$ 2,000,000