Goodwill and Other Intangible Assets - Company's intangible assets (other than goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Goodwill and Other Intangible Assets
GROSS CARRYING AMOUNT	$ 681,152	$ 523,617
ACCUMULATED AMORTIZATION	(169,329)	(127,172)
Finite-Lived Intangible Assets, Net, Total	$ 511,823	396,445
Acquired software
Goodwill and Other Intangible Assets
WEIGHTED AVERAGE AMORTIZATION PERIOD (IN YEARS)	14 years 4 months 17 days
GROSS CARRYING AMOUNT	$ 127,123	24,275
ACCUMULATED AMORTIZATION	(12,258)	(8,099)
Finite-Lived Intangible Assets, Net, Total	$ 114,865	16,176
Purchase software for internal use
Goodwill and Other Intangible Assets
WEIGHTED AVERAGE AMORTIZATION PERIOD (IN YEARS)	2 years 8 months 15 days
GROSS CARRYING AMOUNT	$ 31,477	24,009
ACCUMULATED AMORTIZATION	(20,137)	(13,930)
Finite-Lived Intangible Assets, Net, Total	$ 11,340	10,079
Non-compete agreements
Goodwill and Other Intangible Assets
WEIGHTED AVERAGE AMORTIZATION PERIOD (IN YEARS)	1 year 8 months 23 days
GROSS CARRYING AMOUNT	$ 1,391	1,353
ACCUMULATED AMORTIZATION	(1,247)	(1,145)
Finite-Lived Intangible Assets, Net, Total	$ 144	208
Tradename
Goodwill and Other Intangible Assets
WEIGHTED AVERAGE AMORTIZATION PERIOD (IN YEARS)	15 years 4 months 9 days
GROSS CARRYING AMOUNT	$ 56,483	40,683
ACCUMULATED AMORTIZATION	(9,142)	(6,845)
Finite-Lived Intangible Assets, Net, Total	$ 47,341	33,838
Customer relationships
Goodwill and Other Intangible Assets
WEIGHTED AVERAGE AMORTIZATION PERIOD (IN YEARS)	11 years 14 days
GROSS CARRYING AMOUNT	$ 464,678	433,297
ACCUMULATED AMORTIZATION	(126,545)	(97,153)
Finite-Lived Intangible Assets, Net, Total	$ 338,133	$ 336,144