CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 96,311	$ 85,833
Short-term investments	2,995	6,797
Accounts receivable, net of allowance for doubtful accounts of $475 at both March 31, 2018 and December 31, 2017	35,605	50,629
Deferred commissions - current	8,412	9,285
Prepaid expenses and other current assets	6,892	5,510
TOTAL CURRENT ASSETS	150,215	158,054
Property and equipment-net	8,205	8,812
Deferred commissions - noncurrent	9,022	9,123
Goodwill	5,475	5,475
Other assets	2,737	2,976
TOTAL ASSETS	175,654	184,440
Current liabilities:
Accounts payable	1,259	1,369
Accrued expenses	16,119	25,070
Unearned revenue - current	57,559	55,105
Customer arrangements with termination rights	17,187	19,546
TOTAL CURRENT LIABILITIES	92,124	101,090
Long-term liabilities:
Unearned revenue - noncurrent	23,366	21,917
Other long-term liabilities	1,784	1,881
TOTAL LIABILITIES	117,274	124,888
Commitments and contingencies (Note 11)
Stockholders' equity:
Common stock, $0.0001 par value, 300,000,000 shares authorized, 100,608,155 shares and 97,203,950 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively	11	10
Additional paid-in capital	435,722	420,525
Accumulated deficit	(377,353)	(360,983)
TOTAL STOCKHOLDERS' EQUITY	58,380	59,552
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 175,654	$ 184,440