CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
CURRENT ASSETS:
Trade receivables, allowance for uncollectible accounts	$ 1,035	$ 892
STOCKHOLDERS’ EQUITY:
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares issued	0	0
Common stock, no par value
Common stock, shares authorized	100,000	100,000
Common stock, shares issued	42,586	42,489
Developed Technology Rights [Member]
OTHER ASSETS:
Intangible assets, accumulated amortization	12,668	8,146
Other Intangible Assets [Member]
OTHER ASSETS:
Intangible assets, accumulated amortization	$ 16,473	$ 14,034