Note 11 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Notes Tables

Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]

	Year Ended December 31,
	201 8			201 7			201 6
United States	$	(71,978	)	$	(77,649	)	$	(15,202	)
Foreign		(31,984	)		(18,431	)		26,658
Total	$	(103,962	)	$	(96,080	)	$	11,456

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

	Year Ended December 31,
	201 8			2017			2016
Current:
U.S. Federal	$	—		$	96		$	938
U.S. State		42			51			(22	)
Foreign		375			1,105			35
		417			1,252			951
Deferred:
U.S. Federal		(6,734	)		(11,312	)		(16,755	)
U.S. State		—			(613	)		—
Foreign		(1,894	)		(10,503	)		747
		(8,628	)		(22,428	)		(16,008	)
Total	$	(8,211	)	$	(21,176	)		(15,057	)

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Year Ended December 31,
	201 8			2017			2016
Expenses (benefit) at statutory rate	$	(21,832	)	$	(32,562	)	$	3,895
State income taxes		594			(585	)		222
Research and development credits		(13,283	)		(12,983	)		(8,566	)
Change in valuation allowance		13,757			40,028			9,768
Impact of foreign operations		5,925			(1,951	)		(13,570	)
Unrecognized tax benefits		5,340			3,596			3,151
Stock-based compensation		(381	)		(10,248	)		(9,925	)
Prior year return to provision adjustment		1,422			1,105			(524	)
Effect of U. S. tax law change		—			(4,602	)		—
Impairment of intangibles		—			(2,328	)		—
Other		247			(646	)		492
	$	(8,211	)	$	(21,176	)	$	(15,057	)

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	December 31,
	201 8			201 7
Deferred tax assets
Net operating loss carry forwards	$	39,888		$	34,366
Research and development credits		69,320			62,118
Stock-based compensation		9,055			6,021
Accrued expenses and allowances		2,334			2,004
Amortization and depreciation		1,408			4,910
Other temporary differences		6,411			4,018
Foreign tax credit		2,338			2,557
Valuation allowance		(92,315	)		(78,538	)
Total deferred tax assets		38,439			37,456
Deferred tax liabilities
Acquired intangible assets		(22,593	)		(26,602	)
Acquired tangible assets		—			(255	)
Convertible debt		(11,596	)		(15,213	)
Other deferred tax liabilities		(603	)		(68	)
Total deferred tax liabilities		(34,792	)		(42,138	)
Deferred tax assets ( liabilities ) , net	$	3,647		$	(4,682	)

Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]

	Year Ended December 31,
	201 8			2017			2016
Balance as of January 1	$	47,606		$	56,503		$	46,453
Increases based on tax positions related to the current year		5,747			4,656			5,450
Increases (decreases) based on tax positions of prior year		708			(13,452	)		(1,766	)
Gross increases for acquired unrecognized tax benefits		—			—			6,585
Statute of limitation expirations		(118	)		(101	)		(219	)
Balance as of December 31	$	53,943		$	47,606		$	56,503