Reconciliation for Liabilities Measured at Fair Value on Recurring Basis using Significant Unobservable Inputs (Level Three) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Common stock warrant liability [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 3,800	$ 1,400	$ 2,350	$ 1,403
Income (Expense) Realized in Earnings	(3,700)	(600)	(5,150)	(597)
Transfers In/Out of Level 3
Purchases
Issuances
Settlements
Ending Balance	7,500	2,000	7,500	2,000
Contingent consideration
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		3,671		3,597
Income (Expense) Realized in Earnings		(75)		(149)
Transfers In/Out of Level 3
Purchases
Issuances
Settlements
Ending Balance		$ 3,746		$ 3,746