Schedule of Deferred Revenue and Customer Advances (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Deferred Revenue Arrangement
Customer advances	$ 44,152	$ 70,001
Maintenance, training and extended warranty	50,208	33,953
Undelivered elements	7,200	7,939
Acceptance		318
Total deferred revenue and customer advances	$ 101,560	$ 112,211

Refundable consideration, usually cash, held by the entity pending satisfactory completion of the entity's obligations or pending the closing of a contract.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.15a)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant