INCOME TAXES - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Taxes [Line Items]
Deferred tax benefit	$ (5,764,000)	$ 407,000	$ (152,000)
Deferred tax benefit, federal	(6,002,000)
Voxel acquisition - intangible assets (non-amortizable)	6,100,000
Net non-current deferred income tax assets (liabilities)	11,700,000
Valuation allowances, decrease during the period	2,400,000
Unrecognized tax benefits to reverse over the next twelve months	0
Unrecognized tax position, income tax penalties and interest accrued	48,000	0
Federal
Income Taxes [Line Items]
Net operating loss carryforwards	180,700,000
Operating loss carryforwards expiration dates	beginning 2018 through 2026
Net operating loss carryforwards related to the deduction of stock-based compensation	20,300,000
Alternative minimum tax and research and development tax credit carryforwards	1,000,000
Valuation allowance against U.S. deferred tax assets	119,700,000
Valuation allowance against foreign deferred tax assets	3,700,000
Years under examination	tax years 2008 through 2010
Federal | Alternative Minimum Tax Credits
Income Taxes [Line Items]
Operating loss carryforwards expiration dates	indefinite carryforward period
Federal | Research and Development Credits
Income Taxes [Line Items]
Operating loss carryforwards expiration dates	begin to expire in 2026
Foreign
Income Taxes [Line Items]
Net operating loss carryforwards	13,600,000
Operating loss carryforwards expiration dates	begin to expire in 2012
Years under examination	years prior to 2008
Voxel Holdings Incorporated
Income Taxes [Line Items]
Deferred tax benefit	(6,100,000)
Deferred tax benefit, federal	$ (6,002,000)