Organization and Summary of Significant Accounting Policies Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	$ 4,547	$ 5,477	$ 5,900
Bad debt expense	1,167	838	1,007
Write-offs, net of recoveries	(1,706)	(1,768)	(1,430)
Balance at end of year	4,008	4,547	5,477
Inventory Valuation Reserve [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	7,103	7,520	7,073
Provision for inventory write-downs	1,535	1,538	3,852
Deductions for inventory write-offs	(2,235)	(1,955)	(3,405)
Balance at end of year	$ 6,403	$ 7,103	$ 7,520