Income Taxes (Tables)

12 Months Ended

Dec. 31, 2013

Income Taxes

Schedule of components of the income tax benefit

The components of the income tax benefit were as follow, in thousands:

	Year Ended December 31,
	2013		2012		2011
Current
Federal	$	—	$	—	$	14,090
State		—		—		2,155
Deferred
Federal		—		—		—
State		—		—		—
Total	$	—	$	—	$	16,245

Schedule of reconciliation of the expected income tax benefit computed using the federal statutory income tax rate to the entity's effective income tax rate

A reconciliation of the expected income tax benefit computed using the federal statutory income tax rate to the Company's effective income tax rate is as follows, in thousands:

	Year Ended December 31,
	2013			2012			2011
Income tax (benefit) computed at federal statutory tax rate	$	(32,286	)	$	(16,270	)	$	(13,419	)
Permanent items		340			396			57
State taxes		(4,772	)		(2,487	)		(2,155	)
Change in valuation allowance		31,526			18,754			—
Uncertain tax position		5,411			(64	)		129
Research and development credits		(156	)		—			(857	)
Other		(63	)		(329	)		—
Income tax benefit	$	—		$	—		$	(16,245	)

Schedule of Significant components of the entity's deferred tax assets (liabilities)

The significant components of the Company's deferred tax assets (liabilities) were as follow, in thousands:

	As of December 31,
	2013			2012
Deferred tax assets:
Net operating loss carryforward	$	58,047		$	32,714
Deferred rent credit		615			477
Accrued compensation and non-qualified stock options		1,986			59
Deferred financing costs		319			—
Depreciation and amortization		337			282
Research and development credits		4,167			3,901
Capitalized overhead into inventory (UNICAP §263A)		282			—
Other		151			789
Valuation allowance		(59,823	)		(38,222	)
Net deferred tax asset		6,081			—
Deferred tax liability:
Debt discount on convertible notes		(6,081	)		—
Net deferred taxes	$	0		$	0

Schedule of reconciliation of the beginning and ending amount of gross unrecognized tax benefits

A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows, in thousands:

	Year Ended December 31,
	2013		2012			2011
Balance as of January 1	$	688	$	752		$	642
Gross increases related to prior-year tax positions		23		—			—
Gross increases (decrease) related to current-year tax positions		9,117		(64	)		110
Balance as of December 31	$	9,828	$	688		$	752