Note 4 - Accounts Receivable and Accounts Receivable Allowance (Tables)

6 Months Ended

Jun. 30, 2018

Notes Tables

Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]

	June 30,  2018			December 31, 2017
Accounts receivable	$	207,436		$204,259
Allowance		(14,322	)	(14,799)
Accounts receivable, net	$	193,114		$189,460

Movement in Valuation Allowances and Reserves Roll Forward [Table Text Block]

	June 30,  2018			December 31, 2017
Balance--beginning of period	$	14,799		$	10,772
Provision		10,332			20,233
Charge-offs		(10,809	)		(16,206	)
Balance--end of period	$	14,322		$	14,799