Schedule of Deferred Revenue (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Deferred Revenue Arrangement [Line Items]
Current deferred revenue	$ 74,784	$ 73,840
Long-term deferred revenue	17,423	15,367
Total deferred revenue	92,207	89,207
Software License Arrangement
Deferred Revenue Arrangement [Line Items]
Current deferred revenue	13,686	15,005
Long-term deferred revenue	17,312	13,532
Maintenance
Deferred Revenue Arrangement [Line Items]
Current deferred revenue	52,761	50,916
Professional Services And Other
Deferred Revenue Arrangement [Line Items]
Current deferred revenue	8,337	7,919
Maintenance And Professional Services
Deferred Revenue Arrangement [Line Items]
Long-term deferred revenue	$ 111	$ 1,835