Details of Selected Balance Sheet Accounts Inventories (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Raw materials and subassemblies	$ 56,252	$ 54,168
Work-in-process	2,428	2,297
Finished goods	27,285	33,263
Reserve for excess and obsolete inventories	(31,256)	(32,555)
Total	$ 54,709	$ 57,173