Acquisitions - Narrative (Details) - USD ($)		3 Months Ended		9 Months Ended
	Feb. 01, 2019	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill		$ 120,000,000		$ 120,000,000	$ 23,000,000
Goodwill adjustment				55,000,000
Pacific Union
Business Acquisition [Line Items]
Cash consideration	$ 116,000,000
Goodwill	40,000,000		$ 40,000,000
Increase to payables and other liabilities			11,000,000
Increase to fair value of intangible assets			2,000,000
Property and equipment wrote off			2,000,000
Goodwill adjustment			11,000,000
Acquisition costs		0		4,000,000
Revenue since acquisition		95,000,000		213,000,000
Income from acquisition		$ 58,000,000		108,000,000
Salaries, Wages and Benefits | Pacific Union
Business Acquisition [Line Items]
Acquisition costs				2,000,000
General and Administrative Expense | Pacific Union
Business Acquisition [Line Items]
Acquisition costs				$ 2,000,000
Originations Segment | Pacific Union
Business Acquisition [Line Items]
Goodwill			28,000,000
Servicing Segment | Pacific Union
Business Acquisition [Line Items]
Goodwill			$ 12,000,000
Minimum | Pacific Union
Business Acquisition [Line Items]
Change in contingent consideration	0
Maximum | Pacific Union
Business Acquisition [Line Items]
Change in contingent consideration	$ 16,000,000