Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities
Net loss	$ (29,423)	$ (20,684)	$ (26,733)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	19,624	9,750	7,220
Stock-based compensation expense	21,930	15,823	12,499
Charge related to execution of new lease agreement			884
Changes in operating assets and liabilities:
Increase in accounts receivable, net	(5,634)	(6,885)	(625)
Decrease (increase) in prepaid expenses and other assets	1,549	(1,090)	(4,876)
Increase (decrease) in accounts payable and accrued expenses	3,504	(2,459)	2,366
Increase in accrued compensation and related benefits	2,504	3,086	4,317
Increase in deferred revenue	1,661	528	703
(Increase) decrease in payments to university clients	(13,239)	2,234	(3,664)
Increase (decrease) in other liabilities, net	4,763	4,907	(1,608)
Other	867		250
Net cash provided by (used in) operating activities	8,106	5,210	(9,267)
Cash flows from investing activities
Purchase of a business, net of cash acquired	(97,102)
Purchases of property and equipment	(27,316)	(7,648)	(1,256)
Additions of amortizable intangible assets	(23,823)	(16,728)	(12,358)
Advances made to university clients	(1,950)
Advances repaid by university clients	817
Other		(142)	(2,331)
Net cash used in investing activities	(149,374)	(24,518)	(15,945)
Cash flows from financing activities
Proceeds from issuance of common stock, net of offering costs	189,463		117,112
Proceeds from exercise of stock options	6,615	4,859	5,336
Proceeds from debt	3,500
Payments on debt	(1,517)
Tax withholding payments associated with settlement of restricted stock units	(1,309)	(378)	(436)
Other		(172)
Net cash provided by financing activities	196,752	4,309	122,012
Effect of exchange rate changes on cash	(844)
Net increase (decrease) in cash and cash equivalents	54,640	(14,999)	96,800
Cash and cash equivalents, beginning of period	168,730	183,729	86,929
Cash and cash equivalents, end of period	$ 223,370	$ 168,730	$ 183,729

The cashflows for advances from or to customers.

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