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Note 8 - Employee Benefit Plans (Details) - Investment Policy Allocation | 12 Months Ended
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Dec. 31, 2015
Large Cap U.S. Equity [Member] |
Note 8 - Employee Benefit Plans (Details) - Investment Policy Allocation [Line Items] |
Asset categories | 10.00%
Allocation minimum percentage | 7.00%
Allocation maximum percentage | 13.00%
Small Cap U.S. Equity [Member] |
Note 8 - Employee Benefit Plans (Details) - Investment Policy Allocation [Line Items] |
Asset categories | 5.00%
Allocation minimum percentage | 4.00%
Allocation maximum percentage | 6.00%
Foreign Government Debt Securities [Member] |
Note 8 - Employee Benefit Plans (Details) - Investment Policy Allocation [Line Items] |
Asset categories | 15.00%
Allocation minimum percentage | 11.00%
Allocation maximum percentage | 19.00%
Fixed Income Funds [Member] |
Note 8 - Employee Benefit Plans (Details) - Investment Policy Allocation [Line Items] |
Asset categories | 30.00%
Allocation minimum percentage | 25.00%
Allocation maximum percentage | 35.00%
Real Estate [Member] |
Note 8 - Employee Benefit Plans (Details) - Investment Policy Allocation [Line Items] |
Asset categories | 15.00%
Allocation minimum percentage | 12.00%
Allocation maximum percentage | 18.00%
Hedge Funds [Member] |
Note 8 - Employee Benefit Plans (Details) - Investment Policy Allocation [Line Items] |
Asset categories | 15.00%
Allocation minimum percentage | 12.00%
Allocation maximum percentage | 18.00%
Real Return [Member] |
Note 8 - Employee Benefit Plans (Details) - Investment Policy Allocation [Line Items] |
Asset categories | 10.00%
Allocation minimum percentage | 8.00%
Allocation maximum percentage | 12.00%

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