Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts receivable, allowance for doubtful accounts	$ 4,606	$ 3,163

Amount of valuation allowance for receivables classified as other, due within one year or the normal operating cycle, if longer.

No definition available.

Name:	us-gaap_AllowanceForDoubtfulOtherReceivablesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant