Basis of Presentation (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents				$ 1,644,054	$ 1,851,253	$ 2,632,235		$ 1,251,456
Payments for business acquisitions				10,400	83,200
Goodwill impairment				0	(20,190)
Customer deposits				589,634		449,474
Contract asset insurance renewals				39,400		38,500
Residential mortgage loans available-for-sale fair value				495,049		564,979
Residential mortgage loans available-for-sale aggregate outstanding principal balance				481,500		539,100
Net gains from the sale of mortgages				$ 77,400	30,900
Variability in future cash flows of derivative instruments in days				60 days
Assets In-Scope Under Accounting Standards Codification 326				$ 186,400		176,200
Interest rate lock commitments
Finite-Lived Intangible Assets [Line Items]
Derivative, notional amount				598,000		367,200
Forward contracts
Finite-Lived Intangible Assets [Line Items]
Derivative, notional amount				887,000		686,400
Whole loan commitments
Finite-Lived Intangible Assets [Line Items]
Derivative, notional amount				$ 160,500		$ 169,600
Innovative Construction Group [Member]
Finite-Lived Intangible Assets [Line Items]
Consideration for business acquisition		$ 104,000
Payments for business acquisitions	$ (10,400)	83,200
Goodwill		48,700
Goodwill impairment					$ (20,190)
Innovative Construction Group [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible asset acquired		27,800
Intangible asset, amortization period				7 years
Innovative Construction Group [Member] | Trade Name
Finite-Lived Intangible Assets [Line Items]
Intangible asset acquired		$ 1,800
Intangible asset, amortization period				5 years
Forecast | Innovative Construction Group [Member]
Finite-Lived Intangible Assets [Line Items]
Payments for business acquisitions			$ 10,400
Revision of Prior Period, Accounting Standards Update, Adjustment [Member] | Retained Earnings
Finite-Lived Intangible Assets [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption (Deprecated 2020-01-31)							$ (700)