Note 10 - Developments in Accounting Pronouncements (Details Textual) - December 31, 2016 [Member] $ in Millions	6 Months Ended
Jun. 30, 2017 USD ($)
Reclassification of Deferred Tax Assets from Current to Noncurrent [Member]
Prior Period Reclassification Adjustment	$ 12.3
Reclassification of Deferred Tax Liabilities from Current to Noncurrent [Member]
Prior Period Reclassification Adjustment	$ 1.3

The amount of a reclassification adjustment made to prior period financial statement amounts.

No definition available.

Name:	us-gaap_PriorPeriodReclassificationAdjustment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration