Organization, Consolidation and Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended								12 Months Ended
	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) Customer Segment	Dec. 31, 2018 USD ($) Customer	Dec. 31, 2017 USD ($) Customer	Jan. 01, 2019 USD ($)
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Operating lease assets	$ 35,896,000								$ 35,896,000			$ 28,500,000
Operating lease liabilities	39,097,000								$ 39,097,000			$ 31,000,000.0
Percentage of revenue accounted for by top 5 customers									11.00%	13.00%	9.00%
Number of customers accounting for more than 10% of revenue | Customer									0	0	0
Number of customers accounting for more than 10% of accounts receivable | Customer									0	0
Cash	99,700,000								$ 99,700,000
Cash equivalents	11,000,000.0								11,000,000.0
Long-term investments	0								0
Money market funds	9,900,000								9,900,000
Investments	0								0
Revenue recognized in the reporting period from performance obligations satisfied in prior periods									0
Revenue expected to be recognized from remaining performance obligations	171,700,000								$ 171,700,000
Remaining performance obligation, explanation									We expect to recognize revenue on approximately 50% of these remaining performance obligations over the next 24 months with the balance recognized thereafter.
Percentage of expected revenue recognition									50.00%
Allowance for doubtful accounts recorded to operations									$ 3,900,000	$ 3,900,000	$ 1,600,000
Revenue, practical expedient, remaining performance obligation, description									We apply the practical expedient to expense sales commissions when the amortization period would have been one year or less.
Amortization of sales commissions									$ 1,900,000
Impairment losses									0
Depreciation and amortization expense	2,277,000	$ 1,937,000	$ 1,859,000	$ 1,914,000	$ 1,997,000	$ 2,179,000	$ 2,235,000	$ 2,202,000	7,987,000	8,613,000	9,060,000
Goodwill, net	62,237,000				62,240,000				$ 62,237,000	62,240,000
Customer's license amortization period									5 years
Number of reportable segments | Segment									3
Advertising expense										2,900,000
Office Equipment
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life									5 years
Furniture and Fixtures
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life									7 years
Leasehold Improvements
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Leasehold improvements useful life									Lesser of their useful lives or the term of the lease.
Balance as of December 31, 2018
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Deferred revenue recognized									$ 80,500,000
Sales Commission
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Deferred commissions	10,400,000								10,400,000
Sales Commission | Other Assets
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Deferred commissions	7,700,000								7,700,000
Sales Commission | Prepaid Expenses
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Deferred commissions	2,700,000								2,700,000
Americas
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Accounts receivable, net	81,800,000				80,500,000				81,800,000	80,500,000
Depreciation and amortization expense									6,961,000	7,601,000	8,324,000
Goodwill, net	54,766,000				54,766,000				54,766,000	54,766,000
EMEA
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Accounts receivable, net	14,600,000				15,200,000				14,600,000	15,200,000
Depreciation and amortization expense									766,000	743,000	527,000
Goodwill, net	5,508,000				5,511,000				5,508,000	5,511,000
APAC
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Accounts receivable, net	4,500,000				4,400,000				4,500,000	4,400,000
Depreciation and amortization expense									260,000	269,000	209,000
Goodwill, net	1,963,000				$ 1,963,000				1,963,000	1,963,000
India
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Operating lease liabilities	13,300,000								13,300,000
Certificates of deposit	$ 1,100,000								1,100,000
Other (Loss) Income, Net
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Foreign exchange gain (loss)									$ (1,000,000.0)	$ 1,300,000	$ (1,800,000)