Note 6 - Related-Party Transactions (Details) - Transactions Between the Company and Affiliates (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Services provided by affiliates:
Services provided by affiliates	$ 7,130,000	$ 6,565,000	$ 19,563,000	$ 18,594,000
Field Merchandiser Services SMS [Member]
Services provided by affiliates:
Services provided by affiliates	5,417,000	5,044,000	14,304,000	14,803,000
Field Management Services [Member]
Services provided by affiliates:
Services provided by affiliates	1,266,000	1,125,000	3,706,000	3,395,000
Field Merchandiser Services NMA [Member]
Services provided by affiliates:
Services provided by affiliates	$ 447,000	$ 396,000	$ 1,553,000	$ 396,000