Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net loss	$ (15,580)	$ (7,682)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,711	1,134
Amortization of debt discount		138
Non-cash interest expense	78
Stock-based compensation expense	5,519	575
Provision for doubtful accounts	124	165
Foreign currency re-measurement (gain) loss	(223)	241
Changes in assets and liabilities:
Accounts receivables	14,048	4,179
Prepaid expenses and other assets	(716)	(778)
Accounts payable	(500)	(688)
Accrued expenses	(7,427)	(3,928)
Deferred revenue	1,540	3,588
Other liabilities	(166)	44
Net cash used in operating activities	(1,592)	(3,012)
Cash flows from investing activities:
Purchases of property and equipment	(1,092)	(573)
Net cash used in investing activities	(1,092)	(573)
Cash flows from financing activities:
Payments of capital lease obligations	(68)	(59)
Taxes paid related to net share settlement of equity awards	(3,087)
Proceeds from employee stock purchase plan	2,096
Proceeds from stock option exercises	547	408
Net cash (used in) provided by financing activities	(512)	349
Effect of exchange rate changes on cash	151	(244)
Net decrease in cash	(3,045)	(3,480)
Cash, beginning of period	86,553	36,823
Cash, end of period	83,508	33,343
Supplemental cash flow information:
Cash paid for income taxes	274	58
Cash paid for interest	$ 1	$ 549