Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net loss from continuing operations	$ (9,086)	$ (16,358)
Total income (loss) from discontinued operations	(136)	7,198
Adjustments required to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	2,675	4,706
Bad debt expense	163	325
Mark-to-market expense	0	148
Compensation expense related to the acquisition contingent consideration	0	1,810
Loss on disposal of property and equipment	21	0
Stock-based compensation expense	1,836	2,065
Deferred tax benefit	0	40
Net changes in operating assets and liabilities:
Decrease in accounts receivable	709	4,742
(Increase)/decrease in prepaid expenses, other current assets and other long-term assets	(776)	161
Increase/(decrease) in accounts payable and accrued expenses	615	(8,892)
Increase/(decrease) in other current liabilities	243	(79)
Increase/(decrease) in deferred rent and security deposits payable	760	(315)
(Decrease)/increase in deferred income	(657)	90
Decrease in other liabilities	(639)	0
Net cash used in operating activities	(4,272)	(4,359)
Cash flows from investing activities:
Purchase of property and equipment	(2,505)	(895)
Acquisition, net of cash received	(4,856)	0
Net cash used in investing activities	(7,361)	(895)
Cash flows from financing activities:
Proceeds from the exercise of stock options awards	1,178	62
Proceeds from issuance of common stock under employee stock purchase plan	239	255
Principal portion of capital lease payments	0	(187)
Treasury stock — repurchase of stock	0	(2,406)
Tax withholdings related to net share settlements of restricted stock unit awards (RSUs)	(1,014)	(709)
Net cash provided by (used in) financing activities	403	(2,985)
Net decrease in cash, cash equivalents and restricted cash	(11,230)	(8,239)
Effect of exchange rate changes in cash, cash equivalents and restricted cash	(140)	462
Cash, cash equivalents and restricted cash at beginning of period	76,320	43,930
Cash, cash equivalents and restricted cash at end of period	64,950	36,153
Supplemental disclosure of cash flow activities:
Cash paid for income taxes	53	74
Cash paid for interest expense	0	90
Supplemental disclosure of non-cash investing and financing activities:
Purchase of property and equipment in accounts payable and accrued expenses	0	72
Contingent consideration related to acquisition	1,443	0
Cash holdback related to acquisition	452	0
Deferred tax liability related to acquisition	1,092	0
Common stock issued for settlement of RSUs	$ 2,834	$ 1,879