Summary of Principal Contractual Obligations (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012
Commitments and Contingencies Disclosure [Line Items]
2012 (remaining six months)	$ 12,736
2013	1,984
2014	714
2015	214
2016 and thereafter	180
Total	15,828
Operating Leases
Commitments and Contingencies Disclosure [Line Items]
2012 (remaining six months)	1,468
2013	1,555
2014	710
2015	214
2016 and thereafter	156
Total	4,103
Purchase Commitment
Commitments and Contingencies Disclosure [Line Items]
2012 (remaining six months)	10,872
2013	363
Total	11,235
Other Contractual Obligations
Commitments and Contingencies Disclosure [Line Items]
2012 (remaining six months)	396
2013	66
2014	4
2016 and thereafter	24
Total	$ 490