Note 3 - Concentration of Credit Risk (Details Textual) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Cash, Uninsured Amount	$ 15	$ 12

The amount of cash as of the balance sheet date that is not insured by the Federal Deposit Insurance Corporation.

No definition available.

Name:	us-gaap_CashUninsuredAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant