Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Income Tax Benefit (Expense)

Income tax expense from continuing operations consists of the following:

	Years Ended December 31,
(in thousands)	2017			2016			2015
Current:
Federal	$	—		$	—		$	—
State	151			52			72
Non-U.S.	603			539			321
Total current expense	754			591			393
Deferred:
Federal	(347		)	—			—
State	91			—			—
Non-U.S.	(241		)	(199		)	(181		)
Total deferred expense	(497		)	(199		)	(181		)
Total income tax expense	$	257		$	392		$	212

Reconciliation of Income Tax Expense (Benefit) at Statutory Federal Income Tax Rate

The following table reconciles the federal statutory income rate to the Company's effective income tax rate:

	Year Ended December 31,
	2017		2016		2015
Tax at U.S. statutory rate	34.00	%	34.00	%	34.00	%
Changes from statutory rate:
State taxes, net of federal benefit	10.21		(10.86	)	3.06
Tax credits	13.28		0.03		1.51
Permanent items	(0.55	)	(11.03	)	(2.09	)
Change in enacted rates	0.98		—		—
Change in valuation allowance	(57.91	)	(13.45	)	(37.11	)
Other	(0.98	)	(0.15	)	0.28
Effective income tax rate	(0.97	)%	(1.46	)%	(0.35	)%

Components of Company's Deferred Tax Assets (Liabilities)

Significant components of the Company’s deferred tax assets (liabilities) consists of the following:

	Year Ended December 31,
(in thousands)	2017			2016
Deferred tax assets:
Net operating loss carryforwards	$	129,184		$	169,203
Start up expenditures	462			929
Tax credits	12,705			8,007
Provision for bad debts	824			1,330
Depreciation and amortization	3,068			6,368
Capital loss carryforwards	12,850			18,961
Stock-based compensation	9,799			10,359
Other	4,449			4,701
Total deferred tax assets	$	173,341		$	219,858
Deferred tax liabilities:
Prepaid assets	$	(1,326	)	$	(1,173	)
Amortization of acquired intangibles	(5		)	(33		)
Amortization of debt discount	(43,083		)	(25,977		)
Goodwill	(633		)	(855		)
Other	(259		)	(313		)
Total deferred tax liabilities	$	(45,306	)	$	(28,351	)
Valuation allowance	$	(127,927	)	$	(191,922	)
Net deferred tax liabilities	$	108		$	(415	)