Revenue from servicing real estate mortgages held by others.

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The maximum percentage ownership of common stock or equity participation in the investee under the equity method of accounting.

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The minimum percentage ownership of common stock or equity participation in the investee under the equity method of accounting.

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- Definition

Loan loss guarantee reserve

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No definition available.

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Loan loss accrual

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- Definition

This element represent the minimum sum of age plus years of service with the company to be eligible for receipt of retirement benefits upon departure from the company.

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No definition available.

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- Definition

Amount, before tax, of realized and unrealized gain (loss) from foreign currency transaction.

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- Definition

Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

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- Definition

Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as held-to-maturity.

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No definition available.

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- Definition

Amount of valuation and qualifying accounts and reserves.

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Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) yr	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Mortgage Banking [Abstract]
Identified intangibles, net of accumulated amortization	$ 785.0	$ 858.5
Mortgage-backed Securities Held-to-maturity, Fair Value Disclosure	$ 698.3	695.3
Real Estate Investments, Net [Abstract]
Minimum ownership percentage in real estate ventures (in hundredths)	1.00%
Maximum ownership percentage in real estate ventures (in hundredths)	10.00%
Foreign Currency Translation [Abstract]
Net foreign currency gains (losses)	$ (10.6)	(6.4)	$ (8.1)
Bank Servicing Fees.	129.6	119.0	101.8
Loan loss guarantee reserve	23.4	24.8
Loan loss accrual	30.9	29.0
Allowance For Doubtful Accounts, Current. [Member]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount	$ 70.7	66.7	67.6	$ 66.5
Share-based Payment Arrangement [Member]
Share Based Compensation Arrangement By Share Based Payment Award Sum Of Age Plus Years Of Service Minimum \| yr	65
ASC Topic 326 Opening Balance Adjustment \| Allowance For Doubtful Accounts, Current. [Member]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount			$ 67.6
Mortgage servicing rights [Member]
Mortgage Banking [Abstract]
Identified intangibles, net of accumulated amortization	$ 492.0	$ 505.1