Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2013

Fair Value Measurements [Abstract]

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

	Assets and Liabilities at Fair Value as of March 31, 2013
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash and cash equivalents	$	34,248	$	—	$	—	$	34,248
Short-term investments	162,915		—		—		162,915
Total cash and cash equivalents and investments	$	197,163	$	—	$	—	$	197,163
Liabilities
Other long-term liabilities	$	—	$	—	$	31,184	$	31,184
Total liabilities	$	—	$	—	$	31,184	$	31,184

	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	1,264
Balance at March 31, 2013	$	31,184
Balance at December 31, 2011	$	55,033
Change in valuation of purchase consideration payable to former Symphony Icon stockholders	2,081
Balance at March 31, 2012	$	57,114