Business Combinations - Summary of Allocation of Purchase Consideration and Estimated Values of Assets Acquired and Liabilities Assumed (Details) - USD ($)						6 Months Ended		12 Months Ended
	May 27, 2020	Mar. 19, 2020	Feb. 25, 2020	Feb. 07, 2020	Jul. 29, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Assets acquired
Goodwill						$ 156,114,000		$ 91,421,000
Consideration paid
Cash paid						44,265,000	$ 6,764,000
Contingent consideration						4,292,000
Connexient
Assets acquired
Accounts receivable				$ 849,000
Prepaid expenses and other current assets				518,000
Property and equipment				9,000
Goodwill				14,343,000
Other assets				238,000
Total assets acquired				25,607,000
Liabilities assumed
Accounts payable				751,000
Accrued expenses				208,000
Deferred revenue				2,420,000
Deferred tax liabilities				2,011,000
Other liabilities				211,000
Net assets acquired				20,006,000
Consideration paid
Cash consideration, net of cash acquired				11,500,000		10,991,000
Fair value of common stock issued				9,015,000
Total				20,200,000		20,006,000
Contingent consideration						0
Connexient | Acquired Technology
Assets acquired
Intangible assets other than goodwill				1,220,000
Connexient | Trade Names
Assets acquired
Intangible assets other than goodwill				630,000
Connexient | Customer Relationships
Assets acquired
Intangible assets other than goodwill				$ 7,800,000
CNL Software Limited
Assets acquired
Accounts receivable			$ 1,979,000
Prepaid expenses and other current assets			640,000
Property and equipment			731,000
Goodwill			28,824,000
Other assets			1,313,000
Total assets acquired			42,217,000
Liabilities assumed
Accounts payable			423,000
Accrued expenses			1,653,000
Deferred revenue			3,110,000
Deferred tax liabilities			1,775,000
Other liabilities			1,276,000
Net assets acquired			33,980,000
Consideration paid
Cash consideration, net of cash acquired			19,800,000			18,030,000
Fair value of common stock issued			15,950,000
Total			35,700,000			33,980,000
CNL Software Limited | Acquired Technology
Assets acquired
Intangible assets other than goodwill			2,150,000
CNL Software Limited | Trade Names
Assets acquired
Intangible assets other than goodwill			1,080,000
CNL Software Limited | Customer Relationships
Assets acquired
Intangible assets other than goodwill			$ 5,500,000
One2Many Group B.V.
Assets acquired
Accounts receivable		$ 521,000
Other current assets		1,441,000
Property and equipment		19,000
Goodwill		10,704,000
Other assets		176,000
Total assets acquired		17,511,000
Liabilities assumed
Accounts payable		72,000
Accrued expenses		636,000
Deferred revenue		1,460,000
Deferred tax liabilities		985,000
Other current liabilities		136,000
Net assets acquired		14,222,000
Consideration paid
Cash consideration, net of cash acquired		5,500,000				6,563,000
Fair value of common stock issued		5,469,000
Total		13,100,000				14,222,000
Contingent consideration		2,190,000
One2Many Group B.V. | Acquired Technology
Assets acquired
Intangible assets other than goodwill		970,000
One2Many Group B.V. | Trade Names
Assets acquired
Intangible assets other than goodwill		580,000
One2Many Group B.V. | Customer Relationships
Assets acquired
Intangible assets other than goodwill		$ 3,100,000
Techwan SA
Assets acquired
Accounts receivable	$ 441,000
Other current assets	235,000
Goodwill	13,380,000
Other assets	254,000
Total assets acquired	21,030,000
Liabilities assumed
Accrued expenses	673,000
Deferred revenue	1,190,000
Deferred tax liabilities	940,000
Other current liabilities	927,000
Net assets acquired	17,300,000
Consideration paid
Cash consideration, net of cash acquired	9,400,000					9,301,000
Fair value of common stock issued	5,074,000
Acquisition-related deferred common stock consideration	895,000
Total	15,500,000					17,300,000
Contingent consideration	2,030,000
Techwan SA | Acquired Technology
Assets acquired
Intangible assets other than goodwill	1,140,000
Techwan SA | Trade Names
Assets acquired
Intangible assets other than goodwill	580,000
Techwan SA | Customer Relationships
Assets acquired
Intangible assets other than goodwill	$ 5,000,000
NC4 Inc. and NC4 Public Sector LLC
Assets acquired
Accounts receivable								2,611,000
Other current assets								530,000
Property and equipment								75,000
Goodwill						$ 40,400,000		40,384,000
Total assets acquired								92,910,000
Liabilities assumed
Deferred revenue								7,540,000
Other current liabilities								917,000
Net assets acquired								84,453,000
Consideration paid
Cash paid								51,655,000
Cash consideration, net of cash acquired					$ 51,700,000
Fair value of common stock issued								32,798,000
Total					$ 84,500,000			84,453,000
NC4 Inc. and NC4 Public Sector LLC | Acquired Technology
Assets acquired
Intangible assets other than goodwill								5,210,000
NC4 Inc. and NC4 Public Sector LLC | Trade Names
Assets acquired
Intangible assets other than goodwill								8,610,000
NC4 Inc. and NC4 Public Sector LLC | Customer Relationships
Assets acquired
Intangible assets other than goodwill								$ 35,490,000