Nominal or face amount used to calculate payments on the derivative asset.

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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Aggregate net fair value of all derivative instruments designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations.

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Nominal or face amount used to calculate payments on the derivative liability.

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Derivative Financial Instruments - Outstanding Balances (Details) - USD ($) $ in Millions	5 Months Ended	7 Months Ended	12 Months Ended
	Dec. 31, 2018	Jul. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative instrument, fair value (less than)	$ 0.1		$ 0.1
Loan sale commitments \| Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Outstanding Notional - Asset	319.0		13.0
Fair Value - Asset	13.5		0.1
Recorded Gains / (Losses)	2.8		0.0
IRLCs \| Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Outstanding Notional - Asset	1,301.0		2,065.0
Fair Value - Asset	47.6		59.3
Recorded Gains / (Losses)	(12.1)		(32.9)
IRLCs \| Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Outstanding Notional - Liability	0.0		7.0
Fair Value - Liability	0.0		0.0
Recorded Gains / (Losses)	0.0		1.1
Forward sales of MBS \| Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Outstanding Notional - Asset	485.0		1,802.0
Fair Value - Asset	0.1		2.4
Recorded Gains / (Losses)	(3.1)		(36.9)
Forward sales of MBS \| Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Outstanding Notional - Liability	2,639.0		1,579.0
Fair Value - Liability	19.3		2.8
Recorded Gains / (Losses)	17.4		7.2
LPCs \| Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Outstanding Notional - Asset	215.0		171.0
Fair Value - Asset	1.7		0.9
Recorded Gains / (Losses)	0.4		(1.0)
LPCs \| Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Outstanding Notional - Liability	90.0		213.0
Fair Value - Liability	0.4		0.6
Recorded Gains / (Losses)	(0.2)		0.9
Treasury futures \| Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Outstanding Notional - Asset	0.0		81.0
Fair Value - Asset	0.0		1.9
Recorded Gains / (Losses)	(0.1)		1.9
Treasury futures \| Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Outstanding Notional - Liability	0.0		128.0
Fair Value - Liability	0.0		1.4
Recorded Gains / (Losses)	(0.1)		(1.4)
Eurodollar futures \| Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Outstanding Notional - Asset	19.0		26.0
Fair Value - Asset	0.0		0.0
Recorded Gains / (Losses)	0.0		0.0
Eurodollar futures \| Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Outstanding Notional - Liability	6.0		17.0
Fair Value - Liability	0.0		0.0
Recorded Gains / (Losses)	$ 0.0		0.0
Interest rate swaps and caps \| Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Outstanding Notional - Asset			0.0
Fair Value - Asset			0.0
Recorded Gains / (Losses)			(0.1)
Interest rate swaps and caps \| Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Outstanding Notional - Liability			0.0
Fair Value - Liability			0.0
Recorded Gains / (Losses)			$ 0.1
Predecessor \| Loan sale commitments \| Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Recorded Gains / (Losses)		$ 10.5
Predecessor \| IRLCs \| Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Recorded Gains / (Losses)		0.4
Predecessor \| IRLCs \| Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Recorded Gains / (Losses)		0.0
Predecessor \| Forward sales of MBS \| Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Recorded Gains / (Losses)		0.9
Predecessor \| Forward sales of MBS \| Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Recorded Gains / (Losses)		(1.0)
Predecessor \| LPCs \| Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Recorded Gains / (Losses)		0.3
Predecessor \| LPCs \| Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Recorded Gains / (Losses)		0.1
Predecessor \| Treasury futures \| Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Recorded Gains / (Losses)		(1.8)
Predecessor \| Treasury futures \| Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Recorded Gains / (Losses)		(1.3)
Predecessor \| Eurodollar futures \| Derivative Financial Instruments, Assets
Derivatives, Fair Value [Line Items]
Recorded Gains / (Losses)		0.0
Predecessor \| Eurodollar futures \| Derivative Financial Instruments, Liabilities
Derivatives, Fair Value [Line Items]
Recorded Gains / (Losses)		$ 0.0