Consolidated Deferred Tax Assets or Liabilities (Detail) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Deferred tax assets:
Temporary timing differences	$ 4,152,000	$ 4,277,000
Net operating loss carryforwards	15,041,000	20,065,000
Tax business credits carryforwards	2,160,000	4,166,000
Total deferred tax assets	21,353,000	28,508,000
Valuation allowance	(18,307,000)	(28,476,000)
Net deferred tax assets	3,046,000	32,000
Deferred tax liabilities:
Goodwill	(72,000)	(48,000)
Acquired intangibles		(89,000)
Net deferred tax assets (liabilities)	$ 2,974,000	$ (105,000)