Basis of presentation and description of business - Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2021		Mar. 31, 2021		Dec. 31, 2020		Jun. 30, 2020		Mar. 31, 2020		Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 226,485	[1]	$ 196,190		$ 194,868	[1],[2]	$ 38,424	[2]			$ 32,375	[2]	$ 39,240	$ 33,912
Trade accounts receivable, net of allowances	66,667		75,882		69,056	[2]	53,275				46,571		30,854
Income taxes receivable	565		632		632	[2]	554				14		65
Deferred contract costs	10,480		9,213		8,284	[2]	5,993				4,621		2,128
Prepaid expenses	14,432		15,009		13,283	[2]	10,880				8,094		6,475
Other current assets	2,687		2,325		1,113	[2]	6,314				3,632		1,107
Total current assets	321,316		299,251		287,236	[2]	115,440				95,307		79,869
Equipment and leasehold improvements, net	17,223		16,779		15,130	[2]	14,044				15,195		9,549
Goodwill	541,850		541,850		541,480	[2]	539,818		$ 539,818		539,818		501,145
Other intangible assets, net	189,021		197,504		202,878	[2]	218,430				235,099		252,171
Deferred contract costs, non-current	25,993		23,638		22,202	[2]	16,631				13,420		7,104
Other assets	28,112		28,898		5,359	[2]	2,557				5,440		2,090
Total assets	1,123,515		1,107,920		1,074,285	[2]	906,920				904,279		851,928
Current liabilities:
Accounts payable	9,037		5,744		6,967	[2]	3,715				3,546		2,343
Accrued liabilities	38,263		28,131		31,916	[2]	26,441				27,269		18,903
Income taxes payable	417		1,066		713	[2]	1,081				819		147
Deferred revenues	180,707		167,868		160,002	[2]	129,853				119,828		85,583
Total current liabilities	228,424		202,809		199,598	[2]	161,090				151,462		106,976
Deferred revenues, non-current	57,750		53,711		45,507	[2]	27,429				20,621		14,442
Deferred tax liability, net	4,306		4,285		5,087	[2]	15,356				18,441		26,614
Debt							201,891				201,319		171,749
Other liabilities	29,076		33,839		13,079	[2]	9,084				11,714		464
Total liabilities	319,556		294,644		263,271	[2]	414,850				403,557		320,245
Commitments and contingencies (Note 8)						[2]
Stockholders’ equity:
Preferred stock	0		0		0	[2]	0				0		0
Common stock	118		118		117	[2]	103				103		103
Additional paid‑in capital	917,116		909,966		903,116	[2]	570,434				568,756		565,372
Accumulated deficit	(113,275)		(96,808)		(92,219)	[2]	(78,467)				(68,137)		(33,792)
Total stockholders’ equity	803,959	[2]	813,276	[2]	811,014	[2]	492,070	[2]	492,140	[2]	500,722	[2]	531,683	565,177
Total liabilities and stockholders’ equity	$ 1,123,515		1,107,920		1,074,285	[2]	906,920				904,279		851,928
As Previously Reported
Current assets:
Cash and cash equivalents			196,190		194,868		38,424				32,433		39,240	33,912
Trade accounts receivable, net of allowances			75,882		69,056		53,275				46,513		30,854
Income taxes receivable			632		632		554				14		65
Deferred contract costs			11,155		9,959		7,270				5,553		2,526
Prepaid expenses			15,009		13,283		10,880				10,935		6,682
Other current assets			2,325		1,113		6,314				3,133		922
Total current assets			301,193		288,911		116,717				98,581		80,289
Equipment and leasehold improvements, net			16,965		12,755		11,494				12,477		9,228
Goodwill			541,850		541,480		539,818				539,818		501,145
Other intangible assets, net			197,504		202,878		218,430				235,099		252,171
Deferred contract costs, non-current			28,774		26,770		20,334				16,234		8,461
Other assets			28,898		5,359		2,557				2,599		2,090
Total assets			1,115,184		1,078,153		909,350				904,808		853,384
Current liabilities:
Accounts payable			5,744		6,967		3,909				3,684		2,343
Accrued liabilities			28,131		31,574		26,099				26,927		18,809
Income taxes payable			1,153		713		1,081				819		147
Deferred revenues			167,868		160,443		130,309				120,089		86,220
Total current liabilities			202,896		199,697		161,398				151,519		107,519
Deferred revenues, non-current			53,711		45,507		27,429				20,621		14,442
Deferred tax liability, net			5,475		6,422		14,913				18,133		26,384
Debt							201,891				201,319		171,749
Other liabilities			33,839		11,046		6,876				9,338		196
Total liabilities			295,921		262,672		412,507				400,930		320,290
Commitments and contingencies (Note 8)
Stockholders’ equity:
Preferred stock			0		0		0				0		0
Common stock			118		117		103				103		103
Additional paid‑in capital			909,966		903,116		570,434				568,756		565,372
Accumulated deficit			(90,821)		(87,752)		(73,694)				(64,981)		(32,381)
Total stockholders’ equity			819,263		815,481		496,843		496,502		503,878		533,094	565,265
Total liabilities and stockholders’ equity			1,115,184		1,078,153		909,350				904,808		853,384
Adjustments | Commissions
Current assets:
Cash and cash equivalents			0		0		0				0		0	0
Trade accounts receivable, net of allowances			0		0		0				0		0
Income taxes receivable			0		0		0				0		0
Deferred contract costs			(1,942)		(1,675)		(1,277)				(932)		(398)
Prepaid expenses			0		0		0				0		0
Other current assets			0		0		0				0		0
Total current assets			(1,942)		(1,675)		(1,277)				(932)		(398)
Equipment and leasehold improvements, net			0		0		0				0		0
Goodwill			0		0		0				0		0
Other intangible assets, net			0		0		0				0		0
Deferred contract costs, non-current			(5,136)		(4,568)		(3,703)				(2,814)		(1,357)
Other assets			0		0		0				0		0
Total assets			(7,078)		(6,243)		(4,980)				(3,746)		(1,755)
Current liabilities:
Accounts payable			0		0		0				0		0
Accrued liabilities			0		0		0				0		0
Income taxes payable			0		0		0				0		0
Deferred revenues			0		0		0				0		0
Total current liabilities			0		0		0				0		0
Deferred revenues, non-current			0		0		0				0		0
Deferred tax liability, net			(1,465)		(1,535)		(1,227)				(916)		(428)
Debt							0				0		0
Other liabilities			0		0		0				0		0
Total liabilities			(1,465)		(1,535)		(1,227)				(916)		(428)
Commitments and contingencies (Note 8)
Stockholders’ equity:
Preferred stock			0		0		0				0		0
Common stock			0		0		0				0		0
Additional paid‑in capital			0		0		0				0		0
Accumulated deficit			(5,613)		(4,708)		(3,753)				(2,830)		(1,327)
Total stockholders’ equity			(5,613)		(4,708)		(3,753)		(3,351)		(2,830)		(1,327)	0
Total liabilities and stockholders’ equity			(7,078)		(6,243)		(4,980)				(3,746)		(1,755)
Adjustments | Other
Current assets:
Cash and cash equivalents			0		0		0				(58)		0	0
Trade accounts receivable, net of allowances			0		0		0				58		0
Income taxes receivable			0		0		0				0		0
Deferred contract costs			0		0		0				0		0
Prepaid expenses			0		0		0				(2,841)		(207)
Other current assets			0		0		0				499		185
Total current assets			0		0		0				(2,342)		(22)
Equipment and leasehold improvements, net			(186)		2,375		2,550				2,718		321
Goodwill			0		0		0				0		0
Other intangible assets, net			0		0		0				0		0
Deferred contract costs, non-current			0		0		0				0		0
Other assets			0		0		0				2,841		0
Total assets			(186)		2,375		2,550				3,217		299
Current liabilities:
Accounts payable			0		0		(194)				(138)		0
Accrued liabilities			0		342		342				342		94
Income taxes payable			(87)		0		0				0		0
Deferred revenues			0		(441)		(456)				(261)		(637)
Total current liabilities			(87)		(99)		(308)				(57)		(543)
Deferred revenues, non-current			0		0		0				0		0
Deferred tax liability, net			275		200		1,670				1,224		658
Debt							0				0		0
Other liabilities			0		2,033		2,208				2,376		268
Total liabilities			188		2,134		3,570				3,543		383
Commitments and contingencies (Note 8)
Stockholders’ equity:
Preferred stock			0		0		0				0		0
Common stock			0		0		0				0		0
Additional paid‑in capital			0		0		0				0		0
Accumulated deficit			(374)		241		(1,020)				(326)		(84)
Total stockholders’ equity			(374)		241		(1,020)		$ (1,011)		(326)		(84)	$ (88)
Total liabilities and stockholders’ equity			$ (186)		$ 2,375		$ 2,550				$ 3,217		$ 299

[1] Includes the three months ended March 31, 2021, which has been revised to correct immaterial errors. See Note 1 for more information.

[2] Certain prior period amounts have been revised to correct immaterial errors. See Note 1 for more information.