Note 5 - Related-party Transactions (Details) - Transactions Between the Company and Affiliates (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Services provided by affiliates:
Services provided by affiliates	$ 7,144	$ 7,682
Field Merchandiser Services (SBS) [Member]
Services provided by affiliates:
Services provided by affiliates	5,499	5,459
Field Management Services [Member]
Services provided by affiliates:
Services provided by affiliates	1,113	1,178
Field Merchandiser Services NMA [Member]
Services provided by affiliates:
Services provided by affiliates	244	502
Office and Vehicle Rental (MPT) [Member]
Services provided by affiliates:
Services provided by affiliates	12	16
Vehicle Rental (MCPT) [Member]
Services provided by affiliates:
Services provided by affiliates	197	145
Field Management Services (NDS Tanitim) [Member]
Services provided by affiliates:
Services provided by affiliates	9	9
Field Merchandiser Services (NDS Reklam) [Member]
Services provided by affiliates:
Services provided by affiliates	$ 70	$ 373