Stock-Based Compensation - Schedule of Company's Stock-based Compensation Expense (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock option expense	$ 5,225	$ 1,269	$ 295
Research and Development Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock option expense	572	153	48
Selling and Marketing Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock option expense	2,930	786	181
General and Administrative Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock option expense	$ 1,723	$ 330	$ 66