CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows used in operating activities:
Net loss	$ (30,183)	$ (29,767)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,066	1,826
Allowance for doubtful accounts	1,429	958
Stock-based compensation	2,922	1,378
Deferred income taxes	172	(287)
Accretion of interest	175	81
Changes in operating assets and liabilities:
Accounts receivable	(2,504)	(2,639)
Prepaid expenses and other current assets	435	(105)
Other assets	(12)	32
Accounts payable	(1,707)	3,748
Accrued expenses and other current liabilities	(1,589)	4,066
Accrued compensation	(1,695)	1,648
Other liabilities	616	1,466
Net cash used in operating activities	(28,875)	(17,595)
Cash flows provided by (used in) investing activities:
Purchase of property and equipment	(778)	(3,466)
Purchase of internal software	(658)	(849)
Purchase of marketable securities	(44,188)
Proceeds from the liquidation/maturity of marketable securities	69,749
Acquisition of business, net of cash acquired		(13,545)
Net cash provided by (used in) investing activities	24,125	(17,860)
Cash flows from financing activities:
Net proceeds from the exercise of stock options	590	261
Payment of deferred offering costs		(2,411)
Proceeds from borrowing under bank and other debt	5,500	6,800
Repayment of bank loan	(625)	(208)
Net cash provided by financing activities	5,465	4,442
Net increase (decrease) in cash and cash equivalents	715	(31,013)
Cash and cash equivalents at beginning of the period	55,066	46,436
Cash and cash equivalents at end of the period	55,781	15,423
Interest paid	$ 1,050	$ 920