Changes In Accumulated Other Comprehensive Income (Loss) By Component (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Shareholders' equity	$ 1,117,086	$ 1,052,795	$ 956,816	$ 920,964
Unrealized gains (losses) arising during period, before tax	501	28,531
Income tax effect	155	(7,418)
Other comprehensive income (loss) before reclassifications	656	21,113
Reclassification adjustments for losses (gains) included in net income, before tax	(6,986)	406
Income, tax effect	1,816	(106)
Amounts reclassified from accumulated other comprehensive income (loss) to net income	(5,170)	300
Other comprehensive income (loss), net of income tax effect	(4,514)	21,413	(20,965)
Ending balance	1,117,086	1,052,795	956,816
Total
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Shareholders' equity	(5,764)	(1,250)	(22,663)	$ (359)
Other comprehensive income (loss), net of income tax effect	(4,514)	21,413	(20,965)
Ending balance	(5,764)	(1,250)	(22,663)
Unrealized Gains (Losses) on AFS Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Shareholders' equity	23,312	14,287	(21,741)
Unrealized gains (losses) arising during period, before tax	32,273	49,688
Income tax effect	(8,390)	(12,919)
Other comprehensive income (loss) before reclassifications	23,883	36,769
Reclassification adjustments for losses (gains) included in net income, before tax	(20,078)	(1,001)
Income, tax effect	5,220	260
Amounts reclassified from accumulated other comprehensive income (loss) to net income	(14,858)	(741)
Other comprehensive income (loss), net of income tax effect	9,025	36,028
Ending balance	23,312	14,287	(21,741)
Unrealized Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Shareholders' equity	(29,076)	(15,537)	(922)
Unrealized gains (losses) arising during period, before tax	(31,772)	(21,157)
Income tax effect	8,545	5,501
Other comprehensive income (loss) before reclassifications	(23,227)	(15,656)
Reclassification adjustments for losses (gains) included in net income, before tax	13,092	1,407
Income, tax effect	(3,404)	(366)
Amounts reclassified from accumulated other comprehensive income (loss) to net income	9,688	1,041
Other comprehensive income (loss), net of income tax effect	(13,539)	(14,615)
Ending balance	$ (29,076)	$ (15,537)	$ (922)

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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