Income Tax Expense (Income Tax Expense (Benefit)) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Income tax benefit at federal statutory rate	$ (11,043)	$ (5,467)	$ (11,983)
State income tax expenses, net of federal benefit	(1,097)	73	116
Meals and entertainment	279	298	210
Research and development credits	(4,897)	0	0
Stock-based compensation	1,161	546	382
Contingent consideration	(2,696)	2,890	4,658
Foreign tax rate differential	1,418	656	4,736
Net change in valuation allowance	8,930	2,417	2,244
Return to provision true-up	593	(1,347)	0
Unrecognized tax benefits	6,444	0	0
Other, net	846	(76)	168
Income tax (benefit) expense	$ (62)	$ (10)	$ 531