Other Comprehensive Income (Loss) (Components of OCI) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Unrealized gains and losses on available for sale debt securities:
Net unrealized losses arising during the period	$ (116,081)	$ (12,152)
Reclassification adjustment for gains included in net income	0	(230)
Total	(116,081)	(12,382)
Unrealized gains (losses) on derivatives (cash flow hedges)	14,260	6,226
Amortization related to post-retirement obligations	(378)	(150)
Total other comprehensive (loss) income	(102,199)	(6,306)
Unrealized gains and losses on available for sale debt securities:
Net unrealized losses arising during the period	31,110	3,133
Reclassification adjustment for gains included in net income	0	59
Total	31,110	3,192
Unrealized gains (losses) on derivatives (cash flow hedges)	(3,822)	(1,605)
Amortization related to post-retirement obligations	102	41
Total other comprehensive (loss) income	27,390	1,628
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent [Abstract]
Net unrealized (losses) gains arising during the period	(84,971)	(9,019)
Reclassification adjustment for gains included in net income	0	(171)
Total	(84,971)	(9,190)
Unrealized gains (losses) on derivatives (cash flow hedges)	10,438	4,621
Amortization related to post-retirement obligations	(276)	(109)
Total other comprehensive (loss) income	$ (74,809)	$ (4,678)