Estimated Net Operating Loss Carryforwards And Research and Development Credit Carryforwards for Federal and State Tax Reporting Purposes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Net operating loss carryforwards, federal	307,714
Net operating loss carryforwards, Foreign	30,442
Research and development credit carryforwards, federal	17,765
Research and development credit carryforwards, state	2,906
Foreign
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Operating loss expiration date	2020
Minimum | Federal
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Operating loss expiration date	2024
Research and development credit carryforwards expiration date	2018
Minimum | State
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Research and development credit carryforwards expiration date	2025
Maximum | Federal
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Operating loss expiration date	2031
Research and development credit carryforwards expiration date	2032
Maximum | State
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Research and development credit carryforwards expiration date	2027