Note 7 - Debt - Schedule of Debt (Details) (Parentheticals) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021	Mar. 22, 2019
The 100 Million Note Due October 30, 2022 [Member]
Face amount		$ 100.0
Interest rate, stated		1.73%
The 100 Million Note Due October 30, 2022 [Member] | Minimum [Member]
Interest rate, variable		1.35%
The 100 Million Note Due October 30, 2022 [Member] | Maximum [Member]
Interest rate, variable		1.90%
The 165 Million Note Due January 31, 2024 [Member]
Face amount		$ 165.0
Interest rate, stated		2.24%
The 165 Million Note Due January 31, 2024 [Member] | Minimum [Member]
Interest rate, variable		1.35%
The 165 Million Note Due January 31, 2024 [Member] | Maximum [Member]
Interest rate, variable		1.90%
The 265 Million Note Due January 31, 2028 [Member]
Face amount	$ 265.0
Interest rate, stated	3.18%
Maturity date	Jan. 31, 2028
The 265 Million Note Due January 31, 2028 [Member] | Minimum [Member]
Interest rate, variable	1.45%
The 265 Million Note Due January 31, 2028 [Member] | Maximum [Member]
Interest rate, variable	2.10%
The 80 Million Note Due June 1, 2027 [Member]
Face amount	$ 80.0	$ 80.0
Interest rate, stated	3.72%	3.72%
Maturity date	Jun. 01, 2027	Jun. 01, 2027
The 19 Million Note Due December 1, 2024 [Member]
Face amount	$ 19.0	$ 19.0
Interest rate, stated	4.15%	4.15%
Maturity date	Dec. 01, 2024	Dec. 01, 2024
The 20.2 Million Note Due June 6, 2023 [Member]
Face amount	$ 20.2	$ 20.2
Interest rate, stated	4.28%	4.28%
Maturity date	Jun. 06, 2023	Jun. 06, 2023
The 14 Million Note Due September 11, 2024 [Member]
Face amount	$ 14.0	$ 14.0
Interest rate, stated	4.34%	4.34%
Maturity date	Sep. 11, 2024	Sep. 11, 2024
The 14.3 Million Note Due September 11, 2024 [Member]
Face amount	$ 14.3	$ 14.3
Interest rate, stated	4.34%	4.34%
Maturity date	Sep. 11, 2024	Sep. 11, 2024
The 15.1 Million Note Due January 6, 2024 [Member]
Face amount	$ 15.1	$ 15.1
Interest rate, stated	4.99%	4.99%
Maturity date	Jan. 06, 2024	Jan. 06, 2024
The 2.6 Million Note Due October 1, 2023 [Member]
Face amount	$ 2.6	$ 2.6
Interest rate, stated	5.46%	5.46%
Maturity date	Oct. 01, 2023	Oct. 01, 2023
The Series A Notes [Member]
Face amount	$ 50.0	$ 50.0	$ 50.0
Interest rate, stated	5.09%	5.09%	5.09%
Maturity date	Mar. 22, 2029
The Series B Notes [Member]
Face amount	$ 50.0	$ 50.0	$ 50.0
Interest rate, stated	5.17%	5.17%	5.17%
Maturity date	Mar. 22, 2029	Mar. 22, 2029
The 1.8 Million Note Due November 28, 2022 [Member]
Face amount	$ 1.8	$ 1.8
Interest rate, stated	3.15%	3.15%
Maturity date	Nov. 28, 2022	Nov. 28, 2022
The 2022 Facility [Member]
Interest rate, variable	1.50%	1.50%
Maturity date	Sep. 16, 2026	Sep. 16, 2026
Basis Point Credit Spread Adjustment	2.10%	2.10%