Other Comprehensive Income - Schedule of Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Before reclassification, net of tax	$ 22,176	$ 35,712	$ (28,209)
Reclassification, net of tax	2,320	1,505	5,324
Net change before tax	32,844	53,045	(32,185)
Net change, tax	(8,348)	(15,828)	9,300
Other comprehensive income (loss), net	24,496	37,217	(22,885)
Unrealized Gains and Losses on AFS Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Before reclassification, before tax	38,477	54,723	(32,123)
Before reclassification, tax	(10,632)	(15,461)	9,191
Before reclassification, net of tax	27,845	39,262	(22,932)
Reclassification adjustment before tax	(524)	150	2,873
Reclassification, tax	147	(31)	(636)
Reclassification, net of tax	(377)	119	2,237
Net change before tax	37,953	54,873	(29,250)
Net change, tax	(10,485)	(15,492)	8,555
Other comprehensive income (loss), net	27,468	39,381	(20,695)
Unrealized Gains and Losses on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Before reclassification, before tax	(3,169)	(1,380)	2,651
Before reclassification, tax	918	391	(777)
Before reclassification, net of tax	(2,251)	(989)	1,874
Reclassification adjustment before tax	2,912	1,808	3,493
Reclassification, tax	(838)	(517)	(999)
Reclassification, net of tax	2,074	1,291	2,494
Net change before tax	(257)	428	6,144
Net change, tax	80	(126)	(1,776)
Other comprehensive income (loss), net	(177)	302	4,368
Net change
Accumulated Other Comprehensive Income (Loss) [Line Items]
Before reclassification, net of tax	(3,418)	(2,561)	(7,151)
Reclassification, net of tax	623	95	593
Net change before tax	(4,852)	(2,256)	(9,079)
Net change, tax	2,057	(210)	2,521
Other comprehensive income (loss), net	(2,795)	(2,466)	(6,558)
Net (losses) gains arising during the period
Accumulated Other Comprehensive Income (Loss) [Line Items]
Before reclassification, before tax	(5,719)	(2,385)	(9,916)
Before reclassification, tax	2,301	(176)	2,765
Before reclassification, net of tax	(3,418)	(2,561)	(7,151)
Amortization of prior service (cost) credit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification adjustment before tax	(136)	(135)	212
Reclassification, tax	38	42	(66)
Reclassification, net of tax	(98)	(93)	146
Amortization of net loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification adjustment before tax	1,003	264	625
Reclassification, tax	(282)	(76)	(178)
Reclassification, net of tax	$ 721	$ 188	$ 447