Acquisitions and Dispositions - Assets Acquired and Liabilities Assumed (Details) $ in Thousands, £ in Millions	Sep. 30, 2023 USD ($)	Apr. 25, 2023 USD ($)	Dec. 31, 2022 USD ($)	Oct. 03, 2022 USD ($)	Oct. 03, 2022 GBP (£)	May 31, 2022 USD ($)	Apr. 19, 2022 USD ($)
Business Acquisition [Line Items]
Goodwill	$ 1,572,489		$ 1,566,956
BNG
Business Acquisition [Line Items]
Cash and cash equivalents							$ 2,766
Accounts receivable							10,147
Other current assets							671
Fixed assets							1,587
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill							(12,740)
Other assets							1,583
Accounts payable							(4,771)
Accruals and other liabilities							(6,880)
Advance billings							(1,159)
Other liabilities							(3,642)
Net liabilities assumed							13,042
Goodwill							24,643
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed Less Deferred Acquisition Consideration, Net							$ 37,685
TMA Direct
Business Acquisition [Line Items]
Accounts receivable						$ 582
Other current assets						669
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill						(13,200)
Accounts payable						(379)
Accruals and other liabilities						(270)
Noncontrolling interests						(2,667)
Net liabilities assumed						11,135
Goodwill						6,569
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed Less Deferred Acquisition Consideration, Net						$ 17,704
Maru Group
Business Acquisition [Line Items]
Cash and cash equivalents				$ 1,033
Accounts receivable				7,374
Other current assets				899
Fixed assets				157
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill				(14,300)
Other assets				1,920
Accounts payable				(4,087)
Accruals and other liabilities				(9,154)
Advance billings				(6,462)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities				(3,328)
Other liabilities				(2,891)
Net liabilities assumed				(239)
Goodwill				26,033
Purchase price consideration				25,794	£ 23.0
Wolfgang
Business Acquisition [Line Items]
Cash and cash equivalents				1,606
Accounts receivable				1,180
Other current assets				100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill				(1,055)
Other assets				46
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities				(278)
Net liabilities assumed				3,709
Goodwill				2,451
Purchase price consideration				6,160
Epicenter
Business Acquisition [Line Items]
Cash and cash equivalents				901
Other current assets				45
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill				(7,300)
Accounts payable				(148)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other				(650)
Net liabilities assumed				7,448
Goodwill				4,416
Purchase price consideration				$ 11,864
Huskies [Member]
Business Acquisition [Line Items]
Goodwill		$ 2,600