Accounting Standards and Significant Accounting Policies (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Mar. 09, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle
Total revenues	$ 459,873,000	$ 285,746,000	$ 1,158,750,000	$ 833,378,000
Recurring revenue percentage of total revenue (percent)			79.00%
Cash and investments	348,400,000		$ 348,400,000
Accounts receivable, net	553,000,000		553,000,000			$ 403,700,000
Allowance for losses	10,600,000		10,600,000			9,300,000
Software licenses, royalties, and software services | TourHealth
New Accounting Pronouncements or Change in Accounting Principle
Total revenues	43,300,000		58,400,000
Data and Insight
New Accounting Pronouncements or Change in Accounting Principle
Goodwill assessed for impairment	75,600,000		75,600,000
Platform Technologies
New Accounting Pronouncements or Change in Accounting Principle
Goodwill assessed for impairment	78,300,000		78,300,000
Unbilled Revenues
New Accounting Pronouncements or Change in Accounting Principle
Accounts receivable, net	147,400,000		147,400,000			140,800,000
Unbilled Revenues | Retention Receivable
New Accounting Pronouncements or Change in Accounting Principle
Accounts receivable, net	8,200,000		8,200,000			$ 13,100,000
Convertible Senior Notes Due 2026 | Senior Notes
New Accounting Pronouncements or Change in Accounting Principle
Debt instrument, interest rate, stated percentage					0.25%
Debt instrument face amount	600,000,000		600,000,000		$ 600,000,000
Revolving Credit Facility | 2021 Credit Agreement
New Accounting Pronouncements or Change in Accounting Principle
Long term debt, gross	842,500,000		842,500,000
Revolving Credit Facility | Senior Unsecured Revolving Credit Facility
New Accounting Pronouncements or Change in Accounting Principle
Long term debt, gross	0		0
Line of credit facility, unused borrowing capacity	$ 500,000,000		$ 500,000,000