Securities - Contractual Maturities on Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Available for Sale, Amortized Cost
Within 1 year	$ 32,439
After 1 year through 5 years	115,340
After 5 years through 10 years	280,303
After 10 years	731,462
Amortized Cost	1,159,544	$ 1,187,778
Available for Sale, Estimated Fair Value
Within 1 year	32,706
After 1 year through 5 years	116,975
After 5 years through 10 years	290,249
After 10 years	735,389
Estimated Fair Value	1,175,319	1,225,083
Held to Maturity, Amortized Cost
Within 1 year	0
After 1 year through 5 years	9,343
After 5 years through 10 years	11,189
After 10 years	97,643
Amortized Cost	118,175	58,127
Held to Maturity, Estimated Fair Value
Within 1 year	0
After 1 year through 5 years	9,293
After 5 years through 10 years	11,672
After 10 years	98,112
Estimated Fair Value	$ 119,077	$ 61,114