CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (21,169,000)	$ (32,689,000)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Stock-based compensation expense	21,079,000	19,147,000
Depreciation	1,617,000	1,757,000
Amortization of intangible assets	124,000	0
Provision for doubtful accounts	94,000
Accretion of premium of investment securities		(13,000)
Impairment of right-of-use assets		1,328,000
Loss on disposal of fixed assets		170,000
Changes in operating assets and liabilities:
Accounts receivable	8,721,000	21,683,000
Deferred commissions	1,166,000	(397,000)
Other current and noncurrent assets	504,000	(2,217,000)
Accounts payable	785,000	772,000
Unearned revenue	(5,273,000)	562,000
Customer arrangements with termination rights	(4,073,000)	(2,389,000)
Accrued expenses and other long-term liabilities	(2,172,000)	(4,384,000)
Net cash provided by operating activities	1,403,000	3,330,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(684,000)	(782,000)
Purchase of incapptic, net of cash acquired	(5,668,000)
Proceeds from maturities of investment securities		1,550,000
Purchase of investment securities		(2,236,000)
Net cash used in investing activities	(6,352,000)	(1,468,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from Employee Stock Purchase Plan	1,946,000	2,057,000
Taxes paid for net settlement of equity awards	(3,542,000)	(4,784,000)
Proceeds from exercise of stock options	505,000	1,720,000
Repurchase of common stock	(684,000)	(6,591,000)
Net cash provided by (used in) financing activities	(1,775,000)	(7,598,000)
NET CHANGE IN CASH AND CASH EQUIVALENTS	(6,724,000)	(5,736,000)
CASH AND CASH EQUIVALENTS-Beginning of period	94,415,000	104,613,000
CASH AND CASH EQUIVALENTS-End of period	87,691,000	98,877,000
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Cash paid for income taxes	910,000	679,000
Lease payments for amounts included in the measurement of lease liabilities	3,440,000	3,688,000
SUPPLEMENTAL DISCLOSURES OF NONCASH FINANCING ACTIVITIES:
Value of shares issued under Bonus Plans	4,765,000	6,374,000
Value of shares issued under the Employee Stock Purchase Plan	2,151,000	2,047,000
Unpaid property and equipment purchases	$ 20,000	$ 106,000