Note 7 - Employee Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended
Jan. 31, 2015	Dec. 31, 2015
Note 7 - Employee Benefit Plans (Details) [Line Items]
Defined Benefit Plan, Contributions by Employer	$ 5.0
Scenario, Forecast [Member] \| Unfunded Supplemental Executive Retirement Plan [Member]
Note 7 - Employee Benefit Plans (Details) [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year		$ 0.4

The increase in the fair value of plan assets from contributions made by the employer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration