Loans and Allowance for Credit Losses on Loans - Aging Analysis Of The Recorded Investment In Loans (Details)	Sep. 30, 2022 USD ($) loan	Dec. 31, 2021 USD ($) loan
Aging analysis of loan portfolio
Loans	$ 6,958,124,000
Loans		$ 5,782,663,000
Number of loans modified in accordance with CARES Act | loan	1	1
Amount of outstanding loans modified in accordance with CARES Act	$ 36,800,000	$ 36,800,000
Loans modified in accordance with CARES Act, payments due	0
Total Past Due
Aging analysis of loan portfolio
Loans	26,649,000
Loans		2,619,000
30-59 Days Past Due
Aging analysis of loan portfolio
Loans	776,000
Loans		1,923,000
60-89 Days Past Due
Aging analysis of loan portfolio
Loans	182,000
Loans		321,000
Greater Than 90 Days
Aging analysis of loan portfolio
Loans	25,691,000
Loans		375,000
Current.
Aging analysis of loan portfolio
Loans	6,931,475,000
Loans		5,780,044,000
Mortgage warehouse lines of credit
Aging analysis of loan portfolio
Loans	815,084,000
Loans		781,437,000
Mortgage warehouse lines of credit | Current.
Aging analysis of loan portfolio
Loans	815,084,000
Loans		781,437,000
Residential real estate
Aging analysis of loan portfolio
Loans	1,030,075,000
Loans		843,101,000
Residential real estate | Total Past Due
Aging analysis of loan portfolio
Loans	861,000
Loans		1,725,000
Residential real estate | 30-59 Days Past Due
Aging analysis of loan portfolio
Loans	627,000
Loans		1,252,000
Residential real estate | 60-89 Days Past Due
Aging analysis of loan portfolio
Loans	109,000
Loans		287,000
Residential real estate | Greater Than 90 Days
Aging analysis of loan portfolio
Loans	125,000
Loans		186,000
Residential real estate | Current.
Aging analysis of loan portfolio
Loans	1,029,214,000
Loans		841,376,000
Healthcare financing
Aging analysis of loan portfolio
Loans	1,429,675,000
Loans		826,157,000
Healthcare financing | Total Past Due
Aging analysis of loan portfolio
Loans	21,783,000
Healthcare financing | Greater Than 90 Days
Aging analysis of loan portfolio
Loans	21,783,000
Healthcare financing | Current.
Aging analysis of loan portfolio
Loans	1,407,892,000
Loans		826,157,000
Multi-family financing
Aging analysis of loan portfolio
Loans	2,766,950,000
Loans	2,702,042,000	2,702,042,000
Multi-family financing | Current.
Aging analysis of loan portfolio
Loans	2,766,950,000
Loans		2,702,042,000
Commercial and commercial real estate
Aging analysis of loan portfolio
Loans	810,731,000
Loans		520,199,000
Commercial and commercial real estate | Total Past Due
Aging analysis of loan portfolio
Loans	3,778,000
Loans		748,000
Commercial and commercial real estate | 30-59 Days Past Due
Aging analysis of loan portfolio
Loans		591,000
Commercial and commercial real estate | 60-89 Days Past Due
Aging analysis of loan portfolio
Loans		8,000
Commercial and commercial real estate | Greater Than 90 Days
Aging analysis of loan portfolio
Loans	3,778,000
Loans		149,000
Commercial and commercial real estate | Current.
Aging analysis of loan portfolio
Loans	806,953,000
Loans		519,451,000
Commercial and commercial real estate | Government guaranteed SBA loans | 30-59 Days Past Due
Aging analysis of loan portfolio
Loans	0
Loans		3,200,000
Commercial and commercial real estate | Government guaranteed SBA loans | Greater Than 90 Days
Aging analysis of loan portfolio
Loans	0
Loans		274,000
Agricultural production and real estate
Aging analysis of loan portfolio
Loans	91,913,000
Loans		97,060,000
Agricultural production and real estate | Total Past Due
Aging analysis of loan portfolio
Loans	132,000
Loans		58,000
Agricultural production and real estate | 30-59 Days Past Due
Aging analysis of loan portfolio
Loans	59,000
Loans		37,000
Agricultural production and real estate | 60-89 Days Past Due
Aging analysis of loan portfolio
Loans	73,000
Loans		21,000
Agricultural production and real estate | Current.
Aging analysis of loan portfolio
Loans	91,781,000
Loans		97,002,000
Consumer and margin loans
Aging analysis of loan portfolio
Loans	13,696,000
Loans		12,667,000
Consumer and margin loans | Total Past Due
Aging analysis of loan portfolio
Loans	95,000
Loans		88,000
Consumer and margin loans | 30-59 Days Past Due
Aging analysis of loan portfolio
Loans	90,000
Loans		43,000
Consumer and margin loans | 60-89 Days Past Due
Aging analysis of loan portfolio
Loans		5,000
Consumer and margin loans | Greater Than 90 Days
Aging analysis of loan portfolio
Loans	5,000
Loans		40,000
Consumer and margin loans | Current.
Aging analysis of loan portfolio
Loans	$ 13,601,000
Loans		$ 12,579,000