Note 7 - Fair Value of Financial Instruments and Concentrations of Credit Risk (Detail) - Allowance for Losses on Accounts Receivable (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Balance at beginning of year	$ 3,161	$ 5,839	$ 5,969
Provision for uncollectible accounts	1,709	2,400	478
Write-offs, net of recoveries	(792)	(5,078)	(608)
Balance at end of year	$ 4,078	$ 3,161	$ 5,839