Business Combinations - Intangible Assets Acquired (Details) - USD ($) $ in Thousands	Nov. 23, 2020	Oct. 26, 2020	Oct. 01, 2020	Feb. 28, 2020
Decision Resources Group
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets				$ 487,400
Decision Resources Group | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets				$ 381,000
Decision Resources Group | Customer relationships | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years				10 years
Decision Resources Group | Customer relationships | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years				21 years
Decision Resources Group | Database and content
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets				$ 50,200
Decision Resources Group | Database and content | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years				2 years
Decision Resources Group | Database and content | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years				7 years
Decision Resources Group | Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets				$ 5,200
Decision Resources Group | Trade names | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years				4 years
Decision Resources Group | Trade names | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years				7 years
Decision Resources Group | Purchased software
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets				$ 23,000
Decision Resources Group | Purchased software | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years				3 years
Decision Resources Group | Purchased software | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years				8 years
Decision Resources Group | Backlog
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets				$ 28,000
Remaining Range of Years				4 years
CPA Global
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets			$ 4,920,317
CPA Global | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets			$ 4,643,306
CPA Global | Customer relationships | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years			17 years
CPA Global | Customer relationships | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years			23 years
CPA Global | Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets			$ 266,224
CPA Global | Technology | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years			6 years
CPA Global | Technology | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years			14 years
CPA Global | Trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets			$ 10,787
CPA Global | Trademarks | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years			2 years
CPA Global | Trademarks | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years			17 years
IncoPat
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets		$ 21,957
IncoPat | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets		$ 19,989
Remaining Range of Years		11 years
IncoPat | Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets		$ 76
Remaining Range of Years		2 years
IncoPat | Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets		$ 1,892
Remaining Range of Years		6 years
Hanlim IPS
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets	$ 8,805
Hanlim IPS | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets	$ 7,832
Hanlim IPS | Customer relationships | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years	11 years
Hanlim IPS | Customer relationships | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Remaining Range of Years	13 years
Hanlim IPS | Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets	$ 15
Remaining Range of Years	2 years
Hanlim IPS | Non-compete agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets	$ 958
Remaining Range of Years	5 years