Organization and Summary of Significant Accounting Policies Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	$ 4,008	$ 4,547	$ 5,477
Bad debt expense	1,110	1,167	838
Write-offs, net of recoveries	(913)	(1,706)	(1,768)
Balance at end of year	4,205	4,008	4,547
Inventory Valuation Reserve [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	6,403	7,103	7,520
Provision for inventory write-downs	3,043	1,535	1,538
Deductions for inventory write-offs	(2,467)	(2,235)	(1,955)
Balance at end of year	$ 6,979	$ 6,403	$ 7,103