Financial Derivatives (Interest Rate Swaps) (Details) - Interest rate swaps - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Long
Derivative [Line Items]
Notional Amount	$ 246,599	$ 253,423
Fair Value	3,410	8,329
Long | 2021 [Member]
Derivative [Line Items]
Notional Amount		12,950
Fair Value		205
Long | 2022 [Member]
Derivative [Line Items]
Notional Amount	53,974	103,974
Fair Value	463	1,413
Long | 2023 [Member]
Derivative [Line Items]
Notional Amount	41,407	48,657
Fair Value	1,094	2,209
Long | 2024 [Member]
Derivative [Line Items]
Notional Amount	76,342	86,342
Fair Value	2,572	4,567
Long | 2026 [Member]
Derivative [Line Items]
Notional Amount	59,640
Fair Value	(295)
Long | 2031
Derivative [Line Items]
Notional Amount	13,736
Fair Value	(251)
Long | 2035
Derivative [Line Items]
Notional Amount	500	500
Fair Value	(43)	(14)
Long | 2040
Derivative [Line Items]
Notional Amount	500	500
Fair Value	(55)	(20)
Long | 2050
Derivative [Line Items]
Notional Amount	500	500
Fair Value	$ (75)	$ (31)
Long | Weighted Average
Derivative [Line Items]
Pay Rate	1.52%	1.48%
Receive Rate	0.10%	0.22%
Remaining Years to Maturity	3 years 1 month 6 days	2 years 5 months 23 days
Long | Weighted Average | 2021 [Member]
Derivative [Line Items]
Pay Rate		1.75%
Receive Rate		0.24%
Remaining Years to Maturity		8 months 15 days
Long | Weighted Average | 2022 [Member]
Derivative [Line Items]
Pay Rate	1.85%	1.07%
Receive Rate	0.00%	0.22%
Remaining Years to Maturity	5 months 1 day	1 year 5 months 23 days
Long | Weighted Average | 2023 [Member]
Derivative [Line Items]
Pay Rate	2.00%	2.00%
Receive Rate	0.12%	0.24%
Remaining Years to Maturity	1 year 5 months 19 days	2 years 3 months 3 days
Long | Weighted Average | 2024 [Member]
Derivative [Line Items]
Pay Rate	1.57%	1.65%
Receive Rate	0.14%	0.22%
Remaining Years to Maturity	3 years 18 days	3 years 8 months 23 days
Long | Weighted Average | 2026 [Member]
Derivative [Line Items]
Pay Rate	0.89%
Receive Rate	0.13%
Remaining Years to Maturity	4 years 9 months 3 days
Long | Weighted Average | 2031
Derivative [Line Items]
Pay Rate	1.32%
Receive Rate	0.13%
Remaining Years to Maturity	9 years 9 months 3 days
Long | Weighted Average | 2035
Derivative [Line Items]
Pay Rate	0.74%	0.74%
Receive Rate	0.09%	0.09%
Remaining Years to Maturity	14 years 21 days	14 years 9 months 21 days
Long | Weighted Average | 2040
Derivative [Line Items]
Pay Rate	0.84%	0.84%
Receive Rate	0.09%	0.09%
Remaining Years to Maturity	19 years 25 days	19 years 9 months 25 days
Long | Weighted Average | 2050
Derivative [Line Items]
Pay Rate	0.90%	0.90%
Receive Rate	0.09%	0.09%
Remaining Years to Maturity	29 years 25 days	29 years 9 months 25 days
Short
Derivative [Line Items]
Notional Amount	$ 1,430,497	$ 408,295
Fair Value	(3,644)	(14,984)
Short | 2021 [Member]
Derivative [Line Items]
Notional Amount		17,500
Fair Value		(231)
Short | 2022 [Member]
Derivative [Line Items]
Notional Amount	64,100	96,533
Fair Value	(269)	(1,535)
Short | 2023 [Member]
Derivative [Line Items]
Notional Amount	691,110	146,012
Fair Value	(3,022)	(4,770)
Short | 2024 [Member]
Derivative [Line Items]
Notional Amount	314,762
Fair Value	391
Short | 2025 [Member]
Derivative [Line Items]
Notional Amount	52,692	66,503
Fair Value	(70)	(1,034)
Short | 2026 [Member]
Derivative [Line Items]
Notional Amount	29,925	11,216
Fair Value	186	(458)
Short | 2027 [Member]
Derivative [Line Items]
Notional Amount	9,732	9,732
Fair Value	360	60
Short | 2028 [Member]
Derivative [Line Items]
Notional Amount	119,634	16,644
Fair Value	(215)	(2,169)
Short | 2029 [Member]
Derivative [Line Items]
Notional Amount	19,152	22,744
Fair Value	(898)	(2,289)
Short | 2030 [Member]
Derivative [Line Items]
Notional Amount	9,585	13,015
Fair Value	270	(369)
Short | 2031
Derivative [Line Items]
Notional Amount	111,409
Fair Value	835
Short | 2035
Derivative [Line Items]
Notional Amount	500	500
Fair Value	41	15
Short | 2036 [Member]
Derivative [Line Items]
Notional Amount	1,100	1,100
Fair Value	37	(47)
Short | 2040
Derivative [Line Items]
Notional Amount	500	500
Fair Value	51	20
Short | 2049 [Member]
Derivative [Line Items]
Notional Amount	5,796	5,796
Fair Value	(1,408)	(2,208)
Short | 2050
Derivative [Line Items]
Notional Amount	500	500
Fair Value	$ 67	$ 31
Short | Weighted Average
Derivative [Line Items]
Pay Rate	0.72%	1.39%
Receive Rate	0.12%	0.23%
Remaining Years to Maturity	3 years 3 months 14 days	3 years 9 months 25 days
Short | Weighted Average | 2021 [Member]
Derivative [Line Items]
Pay Rate		2.75%
Receive Rate		0.24%
Remaining Years to Maturity		2 months 19 days
Short | Weighted Average | 2022 [Member]
Derivative [Line Items]
Pay Rate	0.99%	1.19%
Receive Rate	0.12%	0.22%
Remaining Years to Maturity	5 months 4 days	1 year 1 month 20 days
Short | Weighted Average | 2023 [Member]
Derivative [Line Items]
Pay Rate	0.55%	1.50%
Receive Rate	0.12%	0.23%
Remaining Years to Maturity	1 year 8 months 19 days	2 years 5 months 1 day
Short | Weighted Average | 2024 [Member]
Derivative [Line Items]
Pay Rate	0.43%
Receive Rate	0.13%
Remaining Years to Maturity	2 years 5 months 26 days
Short | Weighted Average | 2025 [Member]
Derivative [Line Items]
Pay Rate	0.86%	0.73%
Receive Rate	0.13%	0.21%
Remaining Years to Maturity	3 years 8 months 8 days	4 years 9 months
Short | Weighted Average | 2026 [Member]
Derivative [Line Items]
Pay Rate	0.88%	1.23%
Receive Rate	0.13%	0.25%
Remaining Years to Maturity	4 years 8 months 19 days	5 years 6 months
Short | Weighted Average | 2027 [Member]
Derivative [Line Items]
Pay Rate	0.49%	0.49%
Receive Rate	0.13%	0.24%
Remaining Years to Maturity	5 years 8 months 23 days	6 years 5 months 23 days
Short | Weighted Average | 2028 [Member]
Derivative [Line Items]
Pay Rate	1.31%	2.39%
Receive Rate	0.13%	0.24%
Remaining Years to Maturity	6 years 8 months 23 days	7 years 3 months 25 days
Short | Weighted Average | 2029 [Member]
Derivative [Line Items]
Pay Rate	1.98%	1.94%
Receive Rate	0.13%	0.23%
Remaining Years to Maturity	7 years 9 months 18 days	8 years 7 months 9 days
Short | Weighted Average | 2030 [Member]
Derivative [Line Items]
Pay Rate	1.09%	1.13%
Receive Rate	0.12%	0.22%
Remaining Years to Maturity	8 years 5 months 23 days	9 years 3 months 14 days
Short | Weighted Average | 2031
Derivative [Line Items]
Pay Rate	1.43%
Receive Rate	0.13%
Remaining Years to Maturity	9 years 8 months 4 days
Short | Weighted Average | 2035
Derivative [Line Items]
Pay Rate	0.78%	0.78%
Receive Rate	0.09%	0.09%
Remaining Years to Maturity	14 years 21 days	14 years 9 months 21 days
Short | Weighted Average | 2036 [Member]
Derivative [Line Items]
Pay Rate	1.45%	1.45%
Receive Rate	0.12%	0.25%
Remaining Years to Maturity	14 years 4 months 20 days	15 years 1 month 17 days
Short | Weighted Average | 2040
Derivative [Line Items]
Pay Rate	0.90%	0.90%
Receive Rate	0.09%	0.09%
Remaining Years to Maturity	19 years 25 days	19 years 9 months 25 days
Short | Weighted Average | 2049 [Member]
Derivative [Line Items]
Pay Rate	2.89%	2.89%
Receive Rate	0.15%	0.23%
Remaining Years to Maturity	27 years 3 months 10 days	28 years 7 days
Short | Weighted Average | 2050
Derivative [Line Items]
Pay Rate	0.98%	0.98%
Receive Rate	0.09%	0.09%
Remaining Years to Maturity	25 years 25 days	29 years 9 months 25 days