Other Comprehensive (Loss) Income - Reclassification adjustments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Securities available for sale and transferred securities: Before Tax Amount
Change in net unrealized gain/loss during the period	$ (74,193)	$ (19,112)
Reclassification adjustment for net gains (losses) included in net income	0	(516)
Total other comprehensive gain (loss)	(91,227)	(19,628)
Cash flow hedge derivatives
Change in net unrealized gain/loss during the period, Before tax	(16,241)
Reclassification adjustment for net gains included in net income, Before tax	(793)
Change in net unrealized gain/loss during the period, Tax (expense) benefit	3,411
Reclassification adjustment for net gains included in net income, Tax (expense) benefit	167
Total other comprehensive gain (loss)	19,158	4,122
Change in net unrealized gain/loss during the period, Net of tax	(12,830)
Reclassification adjustment for net gains included in net income, Net of tax	(626)
Total other comprehensive income (loss)	(72,069)	(15,506)
Securities available for sale and transferred securities: Tax (Expense) Benefit
Change in net unrealized gain/loss during the period	15,580	4,014
Reclassification adjustment for net gains (losses) included in net income		108
Total other comprehensive gain (loss)	19,158	4,122
Securities available for sale and transferred securities:
Change in net unrealized gain/loss during the period	(58,613)	(15,098)
Reclassification adjustment for net gains (losses) included in net income		(408)
Total other comprehensive income (loss)	$ (72,069)	$ (15,506)