Note 12 - Commitments and Contingent Liabilities - Material Adverse Effect on Company's Financial Condition (Details) $ in Thousands	Jun. 30, 2022 USD ($)
Standby Letters of Credit [Member]
Total Amounts Committed	$ 188,732
Less Than 1 Year	188,732
1-3 Years	0
3-5 Years	0
Beyond 5 years	0
Standby Letters of Credit [Member] | Employee Related Commitment [Member]
Total Amounts Committed	51,760
Less Than 1 Year	51,760
1-3 Years	0
3-5 Years	0
Beyond 5 years	0
Standby Letters of Credit [Member] | Environmental Commitment [Member]
Total Amounts Committed	398
Less Than 1 Year	398
1-3 Years	0
3-5 Years	0
Beyond 5 years	0
Standby Letters of Credit [Member] | Other Commitment [Member]
Total Amounts Committed	136,574
Less Than 1 Year	136,574
1-3 Years	0
3-5 Years	0
Beyond 5 years	0
Surety Bond [Member]
Total Amounts Committed	621,409
Less Than 1 Year	568,828
1-3 Years	52,581
3-5 Years	0
Beyond 5 years	0
Surety Bond [Member] | Employee Related Commitment [Member]
Total Amounts Committed	81,524
Less Than 1 Year	81,524
1-3 Years	0
3-5 Years	0
Beyond 5 years	0
Surety Bond [Member] | Environmental Commitment [Member]
Total Amounts Committed	535,491
Less Than 1 Year	484,318
1-3 Years	51,173
3-5 Years	0
Beyond 5 years	0
Surety Bond [Member] | Other Commitment [Member]
Total Amounts Committed	4,394
Less Than 1 Year	2,986
1-3 Years	1,408
3-5 Years	0
Beyond 5 years	$ 0