Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Schedule of Components of Income Tax Expense (Benefit)

The components of our income tax expense are as follows (in thousands):



	Year Ended December 31,
	2017			2016			2015
Current
Federal	$	584		$	7,227		$	7,730
State	(88		)	1,829			1,519
Foreign	6			—			—
Total Current	502			9,056			9,249
Deferred
Federal	3,837			(4,283		)	(3,372		)
State	(1,368		)	(546		)	(180		)
Foreign	19			—			—
Total Deferred	2,488			(4,829		)	(3,552		)
Total	$	2,990		$	4,227		$	5,697

Schedule of Effective Income Tax Rate Reconciliation

The difference between the income tax expense at the federal statutory rate and income tax expense in the consolidated statements of operations is as follows:



	Year Ended December 31,
	2017		2016		2015
Federal statutory rate	35.0	%	35.0	%	35.0	%
State income tax expense, net of federal benefits	0.1		4.9		4.5
Nondeductible meals and entertainment	0.6		1.6		1.2
Research and development tax credits	(16.1	)	(10.8	)	(8.9	)
Tax windfall benefits	(36.5	)	—		—
Change in tax rate due to tax reform	27.2		—		—
Other	(1.0	)	(1.3	)	0.8
Effective rate	9.3	%	29.4	%	32.6	%

Schedule of Components of Deferred Tax Assets and Liabilities

The components of our net deferred tax assets (liabilities) are as follows (in thousands):



	December 31,
	2017			2016
Deferred tax assets, non-current
Provision for doubtful accounts	$	714		$	1,046
Accrued expenses	2,362			2,622
Deferred revenue	2,455			3,627
Deferred rent	3,384			4,671
Stock-based compensation	3,613			3,468
Acquisition costs	3,310			4,482
Subsidiary unit compensation	1,413			1,566
Equity investments	116			182
Net operating losses	1,357			2,678
Tax credits	2,546			—
Intangible assets and prepaid patent licenses	156			—
Other	160			107
Total deferred tax assets, non-current	21,586			24,449
Deferred tax liabilities, non-current
Intangible assets and prepaid patent licenses	(74		)	(2,780		)
Depreciation	(2,917		)	(4,649		)
Contingent liability	(171		)	(268		)
Total deferred tax liabilities, non-current	$	(3,162	)	$	(7,697	)
Net deferred tax assets, non-current	$	18,424		$	16,752

Schedule of Unrecognized Tax Benefits Roll Forward

A reconciliation of the beginning and ending amounts of unrecognized tax benefits (without related interest expense) is as follows (in thousands):



	Year Ended December 31,
	2017			2016			2015
Beginning balance	$	681		$	506		$	208
Additions based on tax positions of the current year	718			197			152
Additions based on tax positions of prior year	373			79			146
Additions resulting from acquisitions	277			—			—
Decreases due to lapse of applicable statute of limitations	(76		)	—			—
Decreases related to settlements of prior year tax positions	—			(101		)	—
Ending balance	$	1,973		$	681		$	506