Note 19 - Stock Repurchase Program (Details Textual) - February 2016 Repurchase Program [Member] - shares shares in Millions	Jun. 30, 2018	Dec. 31, 2017	Feb. 01, 2016
Stock Repurchase Program, Number of Shares Authorized to be Repurchased			45.0
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	7.5	7.5

The remaining number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

No definition available.

Name:	us-gaap_StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant