Investment Securities - Cost basis, unrealized gains and losses, and fair value of debt securities HTM (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
HTM debt securities:
Amortized Cost	$ 1,156,098	$ 420,361
Gross Unrealized Gains	10,509	17,332
Gross Unrealized Losses	17,803	500
Fair Value	1,148,804	437,193
U.S. Treasuries
HTM debt securities:
Amortized Cost	19,803
Gross Unrealized Gains	20
Gross Unrealized Losses	0
Fair Value	19,823
U.S. Government agencies & GSEs
HTM debt securities:
Amortized Cost	70,180	10,575
Gross Unrealized Gains	0	26
Gross Unrealized Losses	1,121	11
Fair Value	69,059	10,590
State and political subdivisions
HTM debt securities:
Amortized Cost	257,688	197,723
Gross Unrealized Gains	4,341	7,658
Gross Unrealized Losses	4,080	242
Fair Value	257,949	205,139
Residential MBS, Agency & GSE
HTM debt securities:
Amortized Cost	381,641	113,400
Gross Unrealized Gains	2,021	4,774
Gross Unrealized Losses	3,687	1
Fair Value	379,975	118,173
Commercial MBS, Agency & GSE
HTM debt securities:
Amortized Cost	411,786	98,663
Gross Unrealized Gains	4,106	4,874
Gross Unrealized Losses	8,915	246
Fair Value	406,977	$ 103,291
Supranational entities
HTM debt securities:
Amortized Cost	15,000
Gross Unrealized Gains	21
Gross Unrealized Losses	0
Fair Value	$ 15,021