Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	3 Months Ended			12 Months Ended
	Dec. 31, 2025	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Net income (loss)				$ 144,697,000	$ (203,597,000)	$ (385,627,000)
Revenue				(1,892,629,000)	(2,026,598,000)	(2,078,925,000)
Pre tax net income				192,524,000	(52,327,000)	(43,920,000)
Marketable securities, unrealized losses				$ 0	0	0
Revenue recognition discontinuation period (more than)	90 days			90 days
Revenue recognition resume period (less than)				60 days
Finite-lived intangible assets, estimated useful lives	10 years			10 years
Amortization expense				$ 15,000,000	16,000,000	16,000,000
United States
Property, Plant and Equipment [Line Items]
Revenue				$ (1,594,983,000)	(1,700,864,000)	$ (1,712,079,000)
Recognition period				5 years
United Kingdom
Property, Plant and Equipment [Line Items]
Recognition period				2 years
Other assets
Property, Plant and Equipment [Line Items]
Unamortized contract costs	$ 28,000,000			$ 28,000,000	$ 28,000,000
Internal-use software
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years			3 years
Minimum
Property, Plant and Equipment [Line Items]
Lease period				3 years
Maximum
Property, Plant and Equipment [Line Items]
Lease period				5 years
Revision of prior period, error correction, adjustment
Property, Plant and Equipment [Line Items]
Net income (loss)		$ 4,000,000	$ 5,000,000				$ 4,000,000
Revenue	$ 5,000,000
Pre tax net income	$ 3,000,000