Note 8 - Lease Obligations (Details Textual) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Operating Lease, Right-of-Use Asset	$ 33.4	$ 37.4
Finance Lease, Right-of-Use Asset, after Accumulated Amortization, Total	$ 25.1	$ 29.4

Amount, after accumulated amortization, of right-of-use asset from finance lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977

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