Note 8 - Benefit Plans (Details Textual)	12 Months Ended
Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Postretirement Life Insurance [Member] \| Life Insurance Contracts [Member]
Gain (Loss) on Investments	$ (7,000)
Postretirement Life Insurance [Member]
Cash Surrender Value of Life Insurance	$ 893,000
Defined Benefit Plans Number of Plans	2
Defined Benefit Plans Retirement Age	65 years
Defined Benefit Plan, Funded Status of Plan	$ (8,925,000)	$ (8,084,000)
Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year	1,061,000
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	$ 500,000
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	25.00%
Defined Contribution Plan, Employer Discretionary Contribution, Percent	3.00%
Pension Contributions	$ 903,000	$ 782,000

Defined benefit plans number of plans

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- Definition

Defined benefit plans retirement age

+ References

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- References

No definition available.

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- Definition

Carrying amount as of the balance sheet date of amounts which could be received based on the terms of the insurance contract upon surrendering life policies owned by the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6812-107765

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- Definition

Amount included in accumulated other comprehensive income (AOCI) expected to be recognized as components of net periodic benefit cost for the fiscal year that follows the most recent annual statement of financial position, including gain (loss), prior service cost (credit), and transition asset (obligation).

+ References

No definition available.

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- Definition

The funded status is measured as the difference between the fair value of plan assets and the benefit obligation. Will normally be the same as the net Defined Benefit Plan, Amounts Recognized in Balance Sheet, Total.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
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- Definition

Amount of employer's best estimate of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position.

+ References

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

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- Definition

This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting and losses recognized for other than temporary impairments (OTTI) of the subject investments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (c)-(e)
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-Publisher FASB
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- Definition

The amount of cash or cash equivalents contributed by the entity to fund its pension plans.

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