Summary of Accrual Activities by Components Related to Company's Restructuring Charges (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Restructuring Cost and Reserve [Line Items]
Accrued expense beginning balance	$ 1,561	$ 1,566
Restructuring charges	8,051	2,048	391
Cash payments	(5,376)	(1,179)
Non-cash write-offs or other adjustments	(2,206)	(874)
Accrued expense ending balance	2,030	1,561	1,566
Employee Severance
Restructuring Cost and Reserve [Line Items]
Accrued expense beginning balance	470
Restructuring charges	3,314	676
Cash payments	(2,419)	(206)
Non-cash write-offs or other adjustments	(61)
Accrued expense ending balance	1,304	470
Facility
Restructuring Cost and Reserve [Line Items]
Accrued expense beginning balance	1,062	1,566
Restructuring charges	967	371
Cash payments	(1,301)	(907)
Non-cash write-offs or other adjustments	(239)	32
Accrued expense ending balance	489	1,062
Accelerated Depreciation and Impairment
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,892	906
Non-cash write-offs or other adjustments	(1,892)	(906)
Other Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Accrued expense beginning balance	29
Restructuring charges	1,878	95
Cash payments	(1,656)	(66)
Non-cash write-offs or other adjustments	(14)
Accrued expense ending balance	$ 237	$ 29