Consolidated and Combined Statements of Equity - USD ($) shares in Millions, $ in Millions	Common stock Cumulative Effect, Period of Adoption, Adjusted Balance	Common stock	Additional paid-in capital Cumulative Effect, Period of Adoption, Adjusted Balance	Additional paid-in capital	Retained earnings Cumulative Effect, Period of Adoption, Adjustment	Retained earnings Cumulative Effect, Period of Adoption, Adjusted Balance	Retained earnings	Accumulated other comprehensive loss Cumulative Effect, Period of Adoption, Adjustment	Accumulated other comprehensive loss Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated other comprehensive loss	Treasury stock Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury stock	Redeemable noncontrolling interests	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Total
Beginning balance at Dec. 31, 2018			$ 1,585.8	$ 1,585.8	$ (1.0)	$ 380.1	$ 381.1	$ 1.0	$ 1.3	$ 0.3	$ (180.7)	$ (180.7)			$ 1,786.5	$ 1,786.5
Beginning balance (shares) at Dec. 31, 2018	153.2	153.2									3.9	3.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]																Accounting Standards Update 2018-02 [Member]
Grant of restricted shares of common stock				(43.7)								$ 43.7
Grant of restricted shares of common stock (in shares)												(0.9)
Forfeitures of restricted shares of common stock				3.1								$ (3.1)
Forfeitures of restricted shares of common stock (shares)												0.1
Tax withholding payments for restricted share vesting				(15.9)												$ (15.9)
Tax withholding payments for restricted share vesting (shares)		(0.1)
Vesting of restricted shares granted from treasury stock				6.7								$ (6.7)
Vesting of restricted shares granted from treasury stock (in shares)												0.1
Purchases of treasury stock												$ (11.9)				(11.9)
Purchases of treasury stock (share)												0.2
Equity based compensation expense				50.8												50.8
Net earnings (losses)							108.8									108.8
Equity-based compensation expense of unconsolidated affiliates							1.7									1.7
Foreign currency translation adjustment										(0.1)						(0.1)	[1]
Unrealized gains losses on interest rate swaps, net										(18.0)						(18.0)
Other comprehensive gains (loss) on investments in unconsolidated affiliates										(3.4)						(3.4)	[2]
Ending balance at Dec. 31, 2019			$ 1,586.8	1,586.8	$ (1.1)	$ 489.5	490.6		$ (20.2)	(20.2)	$ (158.7)	$ (158.7)		$ (1.1)	$ 1,897.4	$ 1,898.5
Ending balance (shares) at Dec. 31, 2019	153.1	153.1									3.4	3.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]																Accounting Standards Update 2016-13 [Member]
Issuance of common stock, net of underwriters' discount and issuance costs				484.2												$ 484.2
Issuance of common stock, net of underwriters' discount and issuance costs (in shares)		7.1
Grant of restricted shares of common stock				(24.9)								$ 24.9
Grant of restricted shares of common stock (in shares)												(0.5)
Forfeitures of restricted shares of common stock				0.6								$ (0.6)
Tax withholding payments for restricted share vesting				(22.4)												(22.4)
Tax withholding payments for restricted share vesting (shares)		(0.1)
Vesting of restricted shares granted from treasury stock				10.2								$ (10.2)
Vesting of restricted shares granted from treasury stock (in shares)												0.2
Equity based compensation expense				39.4												39.4
Contributions received for redeemable noncontrolling interests in Optimal Blue Holdco, LLC													$ 578.0
Deferred income taxes recognized related to the contribution of Compass Analytics to Optimal Blue Holdco, LLC				(1.9)												(1.9)
Fair value adjustment to redeemable noncontrolling interests				(18.3)									18.3			(18.3)
Net earnings (losses)							264.1									264.1
Net losses attributable to redeemable noncontrolling interests													(18.3)			18.3
Equity-based compensation expense of unconsolidated affiliates							3.8									3.8
Foreign currency translation adjustment										(0.1)						(0.1)	[1]
Unrealized gains losses on interest rate swaps, net										(11.7)						(11.7)
Other comprehensive gains (loss) on investments in unconsolidated affiliates										(6.8)						(6.8)	[2]
Ending balance at Dec. 31, 2020				2,053.7			757.4			(38.8)		$ (144.6)	578.0			2,627.7
Ending balance (shares) at Dec. 31, 2020		160.1										3.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Grant of restricted shares of common stock				(35.3)								$ 35.3
Grant of restricted shares of common stock (in shares)												(0.7)
Forfeitures of restricted shares of common stock				3.0								$ (3.0)
Tax withholding payments for restricted share vesting				(25.6)												(25.6)
Tax withholding payments for restricted share vesting (shares)		(0.1)
Vesting of restricted shares granted from treasury stock				12.2								$ (12.2)
Vesting of restricted shares granted from treasury stock (in shares)												0.3
Purchases of treasury stock												$ (146.7)				(146.7)
Purchases of treasury stock (share)												2.0
Equity based compensation expense				41.7												41.7
Fair value adjustment to redeemable noncontrolling interests				(638.8)									638.8			(638.8)
Net earnings (losses)							207.9									207.9
Net losses attributable to redeemable noncontrolling interests													28.0			28.0
Equity-based compensation expense of unconsolidated affiliates							2.9									2.9
Foreign currency translation adjustment										(0.4)						(0.4)	[1]
Unrealized gains losses on interest rate swaps, net										17.0						17.0
Other comprehensive gains (loss) on investments in unconsolidated affiliates										4.7						4.7	[2]
Ending balance at Dec. 31, 2021				$ 1,410.9			$ 968.2			$ (17.5)		$ (271.2)	$ 1,188.8			$ 2,090.4
Ending balance (shares) at Dec. 31, 2021		160.0										4.7

[1] Net of income tax benefit of less than $0.1 million for the years ended December 31, 2021, 2020 and 2019.

[2] Net of income tax expense of $1.6 million and net of income tax benefit of $2.3 million and $1.1 million for the years ended December 31, 2021, 2020 and 2019, respectively