Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2013

Fair Value Measurements [Abstract]

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

	Assets and Liabilities at Fair Value as of June 30, 2013
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash and cash equivalents	$	23,254	$	—	$	—	$	23,254
Short-term investments	152,124		—		—		152,124
Total cash and cash equivalents and investments	$	175,378	$	—	$	—	$	175,378
Liabilities
Other long-term liabilities	$	—	$	—	$	31,661	$	31,661
Total liabilities	$	—	$	—	$	31,661	$	31,661

	Assets and Liabilities at Fair Value as of December 31, 2012
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash and cash equivalents	$	30,423	$	—	$	—	$	30,423
Short-term investments	192,785		—		—		192,785
Total cash and cash equivalents and investments	$	223,208	$	—	$	—	$	223,208
Liabilities
Other long-term liabilities	$	—	$	—	$	29,920	$	29,920
Total liabilities	$	—	$	—	$	29,920	$	29,920

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

	Other Long-term Liabilities
	(in thousands)
Balance at December 31, 2012	$	29,920
Change in valuation of purchase consideration payable to former Symphony Icon stockholders	1,741
Balance at June 30, 2013	$	31,661
Balance at December 31, 2011	$	55,033
Change in valuation of purchase consideration payable to former Symphony Icon stockholders	4,243
Balance at June 30, 2012	$	59,276