Segment and Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 BusinessSegment	Dec. 31, 2010	Dec. 31, 2009
Information about the Company's segments
Product revenue	$ 297,310	$ 263,463	$ 158,379
Service revenue	24,604	27,228	17,348
Depreciation and amortization	9,756	9,809	10,580
Goodwill and intangibles	100,939	105,334	110,941
Operating income (loss)	85,355	75,713	(12,668)
Segment Information (Textual) [Abstract]
Number of reportable segments	2
Minimum percentage of revenue accountability	10.00%	10.00%	10.00%
MVSD [Member]
Information about the Company's segments
Product revenue	264,956	234,052	133,741
Service revenue	8,717	13,362	5,542
Depreciation and amortization	8,445	8,683	9,843
Goodwill and intangibles	94,322	98,252	103,281
Operating income (loss)	94,201	88,342	4,226
SISD [Member]
Information about the Company's segments
Product revenue	32,354	29,411	24,638
Service revenue	15,887	13,866	11,806
Depreciation and amortization	908	757	361
Goodwill and intangibles	6,617	7,082	7,660
Operating income (loss)	10,301	5,064	2,801
Reconciling Items [Member]
Information about the Company's segments
Depreciation and amortization	403	369	376
Operating income (loss)	$ (19,147)	$ (17,693)	$ (19,695)