Loans - Schedule of Outstanding Balance and Related Allowance on Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Loan Balance	$ 5,381,631	$ 2,715,078
ACL Balance		$ 31,243
Loan Purchase [Member]
Loan Balance	75,063
ACL Balance	6,894
Loan Purchase [Member] | Real Estate [Member]
Loan Balance	39,954
ACL Balance	2,374
Loan Purchase [Member] | Real Estate [Member] | Residential [Member]
Loan Balance	15,157
ACL Balance	175
Loan Purchase [Member] | Real Estate [Member] | Commercial Portfolio Segment [Member]
Loan Balance	24,797
ACL Balance	2,199
Loan Purchase [Member] | Other Loans [Member]
Loan Balance	35,109
ACL Balance	4,520
Loan Purchase [Member] | Other Loans [Member] | Commercial [Member]
Loan Balance	29,407
ACL Balance	4,261
Loan Purchase [Member] | Other Loans [Member] | Home Equity and Improvement [Member]
Loan Balance	4,764
ACL Balance	222
Loan Purchase [Member] | Other Loans [Member] | Consumer Portfolio Segment [Member]
Loan Balance	938
ACL Balance	$ 37