Basis of Presentation (Narrative) (Details) $ in Thousands		1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 01, 2018 USD ($)	Apr. 30, 2019 USD ($) lot	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Finite-Lived Intangible Assets [Line Items]
Payments for business acquisitions					$ (163,724)	$ 0
Customer deposits			$ 334,484		334,484		$ 254,624
Contract asset insurance renewals			32,400		32,400
Residential mortgage loans available-for-sale fair value			343,732		343,732		461,354
Residential mortgage loans available-for-sale aggregate outstanding principal balance			331,900		331,900		444,200
Changes in fair value, gain (loss)			(200)		(1,300)	(300)
Net gains from the sale of mortgages			30,400	$ 29,200	$ 54,300	$ 56,200
Variability in future cash flows of derivative instruments in days					60 days
Cumulative effect of accounting change	$ 22,411
Retained Earnings
Finite-Lived Intangible Assets [Line Items]
Cumulative effect of accounting change	$ 22,411
Interest rate lock commitments
Finite-Lived Intangible Assets [Line Items]
Derivative, notional amount			386,000		$ 386,000		285,000
Forward contracts
Finite-Lived Intangible Assets [Line Items]
Derivative, notional amount			577,000		577,000		511,000
Whole loan commitments
Finite-Lived Intangible Assets [Line Items]
Derivative, notional amount			$ 115,200		$ 115,200		$ 187,800
American West Homebuilding Operations
Finite-Lived Intangible Assets [Line Items]
Finished lots acquired | lot		1,200
Additional lot option agreements | lot		2,300
American West Homebuilding Operations | Trade Name
Finite-Lived Intangible Assets [Line Items]
Intangible asset acquired		$ 12,000
Intangible asset, amortization period		20 years