Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2014

Fair Value Measurements [Abstract]

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

	Assets and Liabilities at Fair Value as of March 31, 2014
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash and cash equivalents	$	46,517	$	—	$	—	$	46,517
Short-term investments	51,298		552		—		51,850
Total cash and cash equivalents and investments	$	97,815	$	552	$	—	$	98,367
Liabilities
Other long-term liabilities	$	—	$	—	$	28,852	$	28,852
Total liabilities	$	—	$	—	$	28,852	$	28,852

	Assets and Liabilities at Fair Value as of December 31, 2013
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash and cash equivalents	$	37,499	$	—	$	—	$	37,499
Short-term investments	91,077		552		—		91,629
Total cash and cash equivalents and investments	$	128,576	$	552	$	—	$	129,128
Liabilities
Other long-term liabilities	$	—	$	—	$	27,710	$	27,710
Total liabilities	$	—	$	—	$	27,710	$	27,710

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

	Other Long-term Liabilities
	(in thousands)
Balance at December 31, 2013	$	27,710
Change in valuation of purchase consideration payable to former Symphony Icon stockholders	1,142
Balance at March 31, 2014	$	28,852
Balance at December 31, 2012	$	29,920
Change in valuation of purchase consideration payable to former Symphony Icon stockholders	1,264
Balance at March 31, 2013	$	31,184