Loan Servicing Rights - Components of Loan Servicing Rights and Valuation Allowance (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Servicing asset:
Balance at beginning of period	$ 30,085	$ 28,124
Additions	9,666	3,113
Amortization	(1,505)	(2,975)
Balance before valuation allowance at end of period	38,246	28,262
Valuation allowance:
Balance at beginning of period	(46)	(1,407)
(Additions)/recoveries	45	1,261
Balance at end of period	(1)	(146)
Loan servicing rights, net	38,245	$ 28,116	$ 30,000
First Midwest
Servicing asset:
Additions	$ 7,700