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, 2014
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Net operating loss carryforwards, federal	562,120
Net operating loss carryforwards, state	226,804
Net operating loss carryforwards, Foreign	194,944
Federal
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Research and development credit carryforwards	28,930
State
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Research and development credit carryforwards	4,251
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	2019
Minimum | State
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Operating loss expiration date	2034
Research and development credit carryforwards expiration date	2026
Minimum | Foreign
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Operating loss expiration date	2020
Maximum | Federal
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Operating loss expiration date	2035
Research and development credit carryforwards expiration date	2035
Maximum | State
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Operating loss expiration date	2035
Research and development credit carryforwards expiration date	2030
Maximum | Foreign
Operating Loss Carryforwards And Research And Development Credit Carryforwards [Line Items]
Operating loss expiration date	2022