Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2016

Fair Value Measurements [Abstract]

Fair Value, by Balance Sheet Grouping [Table Text Block]

	Assets and Liabilities at Fair Value as of June 30, 2016
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash and cash equivalents	$	38,410	$	—	$	—	$	38,410
Short-term investments	379,640		11,315		—		390,955
Total cash and cash equivalents and investments	$	418,050	$	11,315	$	—	$	429,365
Liabilities
Accrued liabilities	$	—	$	—	$	13,396	$	13,396
Other long-term liabilities	—		—		10,862		10,862
Total liabilities	$	—	$	—	$	24,258	$	24,258

	Assets and Liabilities at Fair Value as of December 31, 2015
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash and cash equivalents	$	200,526	$	2,463	$	—	$	202,989
Short-term investments	312,888		5,475		—		318,363
Total cash and cash equivalents and investments	$	513,414	$	7,938	$	—	$	521,352
Liabilities
Accrued liabilities	$	—	$	—	$	12,453	$	12,453
Other long-term liabilities	—		—		10,362		10,362
Total liabilities	$	—	$	—	$	22,815	$	22,815

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

Balance at December 31, 2015	$	22,815
Change in valuation of purchase consideration payable to former Symphony Icon stockholders	1,443
Balance at June 30, 2016	$	24,258
Balance at December 31, 2014	$	17,638
Change in valuation of purchase consideration payable to former Symphony Icon stockholders	1,741
Payment of contingent payment obligation with cash	(750		)
Balance at June 30, 2015	$	18,629