Note 6 - Accounting for Share-based Payment Arrangement Compensation (Details Textual) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Stock or Unit Option Plan Expense	$ 273,000us-gaap_StockOptionPlanExpense	$ 211,000us-gaap_StockOptionPlanExpense

The noncash expense that accounts for the value of stock or unit options distributed to employees as compensation.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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