Income Taxes (Effective Income Tax Rate Reconciliation) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	34.00%	34.00%	34.00%
State income taxes, net of federal benefit	(1.40%)	(0.10%)	(0.40%)
Foreign income at other than U.S. rates	(31.00%)	0.80%	0.00%
Stock-based compensation expense	(31.50%)	(4.40%)	(10.00%)
Meals and entertainment	(14.20%)	(1.70%)	(1.30%)
Acquisition and related items	(8.60%)	(0.10%)	0.00%
Non-deductible gifts	(0.80%)	(0.10%)	(0.20%)
Research and development tax credits	42.30%	4.70%	5.60%
Effective Income Tax Rate Reconciliation, Intercompany Financing Charges	(11.20%)	0.00%	0.00%
Other permanent items	(0.50%)	(1.60%)	(0.50%)
Provision to return adjustments	(9.40%)	(0.20%)	0.00%
Change in valuation allowance	120.10%	(32.20%)	(29.90%)
Effective income tax rate	110.20%	(0.90%)	(2.70%)