Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Income Tax Disclosure [Abstract]

Summary of Income Tax Expense

The following table presents the detail of income tax expense as of the periods presented:

	YEAR ENDED DECEMBER 31,
	2016			2015			2014
	(in thousands)
Current:
US - Federal	$	—		$	—		$	—
US - State		(15	)		(56	)		—
Foreign		(63	)		(22	)		(5	)
		(78	)		(78	)		(5	)
Deferred:
US - Federal		(91	)		(88	)		(91	)
US - State		1			—			—
Foreign		—			—			—
		(90	)		(88	)		(91	)
Total income tax expense	$	(168	)	$	(166	)	$	(96	)

Reconciliation of U.S. Federal Statutory Income Tax Rate to Effective Income Tax Rate

The following table presents a reconciliation of the federal statutory rate and our effective tax rate for the periods presented:

	YEAR ENDED DECEMBER 31,
	2016			2015			2014
U.S. Statutory Rate		34.0	%		34.0	%		34.0	%
Change in valuation allowance		(11.8	)		9.9			8.9
State taxes (net of federal benefit)		(4.4	)		3.8			(33.6	)
Federal research and development credit		67.4			(60.8	)		(136.0	)
Incentive stock options		(46.2	)		19.5			83.6
Unrecognized tax benefits		(47.1	)		28.8			34.0
Preferred stock warrant revaluation		12.6			(22.4	)		34.4
Other, net		(15.5	)		2.9			(1.0	)
Effective income tax rate		(11.0)	%		15.7	%		24.3	%

Summary of Significant Components Deferred Tax Assets and Liabilities

The following table presents the significant components of our deferred tax assets and liabilities as of the dates presented:

	DECEMBER 31,
	2016			2015
	(in thousands)
Net operating loss carryforwards (1) (2)	$	34,287		$	33,783
Credit carryforwards (2)		6,492			5,693
Depreciation and amortization		—			594
Capitalized research and development		6,992			8,164
Deferred rent		1,825			223
Allowances		767			261
Deferred compensation		1,209			760
Deferred revenue		331			253
Stock compensation (1)		220			323
Deferred tax assets		52,123			50,054
Less: Valuation Allowance		(50,959	)		(50,054	)
Net deferred tax assets	$	1,164		$	—
Deferred Tax Liability:
Goodwill		(766	)		(676	)
Depreciation and Amortization		(1,164	)		—
Deferred tax liabilities		(1,930	)		(676	)
Net deferred tax liability	$	(766	)	$	(676	)
____________
(1)     During the current period, we recorded an increase to the NOL and an increase to the valuation allowance of $727,000 as a result of the adoption of ASU 2016-09, "Improvements to Employee Share-Based Payment Accounting."
(2)     Carryforwards are presented net of associated tax contingencies

Total Balance of Unrecognized Tax Benefits

The following table presents the total balance of unrecognized tax benefits as of the dates presented:

	YEAR ENDED DECEMBER 31,
	2016		2015		2014
	(in thousands)
Unrecognized tax benefits at beginning of the period	$	1,878	$	1,732	$	1,599
Gross increases to tax positions in prior periods		210		—		—
Gross increases to tax positions in current periods		509		146		133
Unrecognized tax benefits at end of the period	$	2,597	$	1,878	$	1,732