Debt Warehouse Facilities (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 52.1	$ 52.1
Warehouse facilities	622.3	622.3	$ 795.7
Agreement expires September 19, 2022, Extension [Member] [Member]
Line of Credit Facility [Line Items]
Line of Credit, Current	226.4	226.4	516.9
Line of Credit Facility, Maximum Borrowing Capacity	700.0	$ 700.0	700.0
Pricing on the Facility based on market rates		BSBY plus 1.30%
Agreement expires September 16, 2022, Extension [Member] [Member]
Line of Credit Facility [Line Items]
Line of Credit, Current	301.7	$ 301.7	74.7
Line of Credit Facility, Maximum Borrowing Capacity	1,200.0	$ 1,200.0	1,200.0
Pricing on the Facility based on market rates		LIBOR plus 1.30%
Agreement expires August 27, 2022, Extension [Member] [Member]
Line of Credit Facility [Line Items]
Line of Credit, Current	94.6	$ 94.6	192.8
Line of Credit Facility, Maximum Borrowing Capacity	300.0	$ 300.0	300.0
Pricing on the Facility based on market rates		LIBOR plus 1.30%
Agreement expires July 30, 2022, Extension
Line of Credit Facility [Line Items]
Line of Credit, Current	0.0	$ 0.0	0.0
Line of Credit Facility, Maximum Borrowing Capacity	$ 400.0	400.0	400.0
Pricing on the Facility based on market rates	LIBOR plus 1.60%
Fannie Mae ASAP program [Member]
Line of Credit Facility [Line Items]
Line of Credit, Current	$ 0.0	$ 0.0	12.5
Debt Instrument, Interest Rate Terms		SOFR plus 1.25%
Line of Credit, Gross [Member]
Line of Credit Facility [Line Items]
Line of Credit, Current	622.7	$ 622.7	796.9
Line of Credit Facility, Maximum Borrowing Capacity	2,600.0	2,600.0	2,600.0
Warehouse Agreement Borrowings [Member]
Line of Credit Facility [Line Items]
Unamortized Debt Issuance Expense	$ 0.4	$ 0.4	$ 1.2

Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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Description of interest rate for borrowing under credit facility. Includes, but is not limited to, terms and method for determining interest rate.

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No definition available.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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The carrying value as of the balance sheet date of the current portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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Carrying value as of the balance sheet date of the outstanding short-term borrowings under a revolving line of credit used by mortgage bankers to finance the origination or purchase of loans.

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