Note 6 - Net Sales by Segment (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Residential Power Products [Member]
Net sales	$ 184,967	$ 183,747	$ 475,268	$ 527,308
Commercial and Industrial Power Products [Member]
Net sales	148,234	146,411	416,577	467,248
Other Products and Services [Member]
Net sales	26,090	22,147	67,624	62,366
Net sales	$ 359,291	$ 352,305	$ 959,469	$ 1,056,922

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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