Goodwill and other intangible assets - Intangible Assets (Details) - USD ($)	3 Months Ended		6 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2020	Mar. 31, 2021	Dec. 31, 2020		Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Value							$ 303,401,000
Accumulated Amortization (in thousands)	$ 117,370,000		$ 117,370,000				100,523,000
Net Carrying Value							202,878,000
Amortization expense	8,500,000	$ 8,300,000	16,900,000	$ 16,700,000
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Value	306,391,000		306,391,000
Net Carrying Value	189,021,000	218,430,000	189,021,000	218,430,000		$ 197,504,000	202,878,000	[1]	$ 235,099,000	$ 252,171,000
Goodwill and Intangible Asset Impairment	0	$ 0	0	$ 0
IPR&D
Indefinite-lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	400,000		$ 400,000
Trademarks
Finite-Lived Intangible Assets [Line Items]
Useful Life			8 years		8 years
Gross Value	34,300,000		$ 34,300,000				34,320,000
Accumulated Amortization (in thousands)	15,578,000		15,578,000				13,454,000
Net Carrying Value	18,722,000		$ 18,722,000				20,866,000
Weighted‑ Average Remaining Useful Life			4 years 3 months 18 days		4 years 9 months 18 days
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Value	214,408,000		$ 214,408,000				214,428,000
Accumulated Amortization (in thousands)	64,893,000		64,893,000				55,810,000
Net Carrying Value	149,515,000		$ 149,515,000				158,618,000
Weighted‑ Average Remaining Useful Life			8 years 2 months 12 days		8 years 8 months 12 days
Customer relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful Life			2 years		2 years
Customer relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful Life			12 years		12 years
Developed technology
Finite-Lived Intangible Assets [Line Items]
Useful Life			5 years		5 years
Gross Value	57,193,000		$ 57,193,000				54,563,000
Accumulated Amortization (in thousands)	36,809,000		36,809,000				31,173,000
Net Carrying Value	20,384,000		$ 20,384,000				23,390,000
Weighted‑ Average Remaining Useful Life			2 years 2 months 12 days		2 years 3 months 18 days
Non-competes
Finite-Lived Intangible Assets [Line Items]
Useful Life			2 years		2 years
Gross Value	90,000		$ 90,000				90,000
Accumulated Amortization (in thousands)	90,000		90,000				86,000
Net Carrying Value	$ 0		$ 0				$ 4,000
Weighted‑ Average Remaining Useful Life			0 years		1 month 6 days

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