Summary of Significant Accounting Policies (Narrative) (Details)			1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 24, 2020 USD ($)	Apr. 23, 2019 USD ($) lot	Jan. 31, 2020	Mar. 31, 2020 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jan. 01, 2018 USD ($)	Dec. 31, 2017 USD ($)
Payments to Acquire Businesses, Gross							$ 83,251,000	$ 163,724,000	$ 0
Goodwill impairment				$ 20,200,000			20,190,000	0	0
Finite-Lived Intangible Assets, Net							94,500,000	84,600,000
Restricted Cash and Cash Equivalents							50,030,000	33,543,000
Intangible assets, accumulated amortization							224,100,000	204,400,000
Intangible assets amortization expense							19,685,000	14,200,000	13,800,000
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months							16,500,000
Future Amortization Expense, Year Two							11,100,000
Future Amortization Expense, Year Three							10,500,000
Future Amortization Expense, Year Four							10,000,000.0
Future Amortization Expense, Year Five							9,300,000
Property and equipment, net							131,744,000	111,713,000
Property and equipment, accumulated depreciation							228,800,000	218,900,000
Depreciation Expense							46,400,000	39,800,000	35,600,000
Advertising Expense							40,300,000	53,900,000	51,000,000.0
Employee benefit plan company contributions							$ 20,400,000	$ 19,100,000	17,900,000
Number of VIEs requiring consolidation							0	0
Residential mortgage loans available-for-sale							$ 564,979,000	$ 508,967,000
Residential mortgage loans available-for-sale aggregate outstanding principal balance							539,100,000	494,100,000
Net gain (loss) from change in fair value							(1,200,000)	(600,000)	700,000
Net gains from the sale of mortgages							$ 247,300,000	129,400,000	111,300,000
Days past contractual term once loans no longer accrue interest income							90 days
Variability in future cash flows of derivative instruments in days							60 days
Customer deposits							$ 449,474,000	294,427,000
Capitalized contract costs							38,500,000	35,100,000
Contract assets										$ 27,700,000
Stockholders' Equity Attributable to Parent							6,569,989,000	5,458,180,000	4,817,782,000		$ 4,154,026,000
Escrow Deposit							$ 6,100,000	6,200,000
Cumulative Effect, Period of Adoption, Adjustment
Stockholders' Equity Attributable to Parent								(735,000)			22,411,000
Minimum | Office Furniture and Equipment [Member]
Property and equipment, useful life							3 years
Minimum | Software and Hardware [Member]
Property and equipment, useful life							3 years
Minimum | Model Park Improvements and Furnishings [Member]
Property and equipment, useful life							1 year
Maximum | Office Furniture and Equipment [Member]
Property and equipment, useful life							10 years
Maximum | Software and Hardware [Member]
Property and equipment, useful life							5 years
Maximum | Model Park Improvements and Furnishings [Member]
Property and equipment, useful life							5 years
Financial Services [Member]
Interest income on mortgage loans							$ 9,200,000	9,700,000	11,300,000
Interest Rate Lock Commitments [Member]
Derivative, Notional Amount							367,200,000	255,300,000
Forward Contracts [Member]
Derivative, Notional Amount							686,400,000	518,200,000
Whole Loan Commitments [Member]
Derivative, Notional Amount							169,600,000	200,700,000
American West Homes [Member] [Member]
Business Combination, Consideration Transferred		$ 163,700,000
Number of Units in Real Estate Property | lot		1,200
Finite-lived Intangible Assets Acquired		$ 12,000,000.0
American West Homes [Member] [Member] | Trade Names [Member]
Weighted average useful life (in years)		20 years
American West Homes [Member] [Member] | Land Option Contracts [Member]
Number of Units in Real Estate Property | lot		2,300
JW Homes (Wieland) [Member]
Goodwill							$ 68,900,000	40,400,000
Innovative Construction Group [Member]
Business Combination, Consideration Transferred	$ 104,000,000.0
Payments to Acquire Businesses, Gross	83,300,000
Goodwill	48,700,000
Innovative Construction Group [Member] | Customer Relationships [Member]
Finite-lived Intangible Assets Acquired	$ 27,800,000
Weighted average useful life (in years)	7 years		7 years
Innovative Construction Group [Member] | Trade Names [Member]
Finite-lived Intangible Assets Acquired	$ 1,800,000
Weighted average useful life (in years)	5 years
Restricted stock [Member]
Share-based compensation vesting period							3 years
Retained Earnings
Stockholders' Equity Attributable to Parent							$ 3,306,057,000	2,220,574,000	$ 1,613,929,000		980,061,000
Retained Earnings | Cumulative Effect, Period of Adoption, Adjustment
Stockholders' Equity Attributable to Parent								(735,000)
Accounting Standards Update 2014-09 [Member] | Retained Earnings | Cumulative Effect, Period of Adoption, Adjustment
Stockholders' Equity Attributable to Parent											$ 22,411,000
Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment
Insurance Receivables, Contract Assets, and Vendor Rebate Receivables recognized							$ 176,200,000
Accounting Standards Update 2016-13 [Member] | Retained Earnings | Cumulative Effect, Period of Adoption, Adjustment
Stockholders' Equity Attributable to Parent								$ (700,000)
Forecast [Member] | Innovative Construction Group [Member]
Payments to Acquire Businesses, Gross					$ 10,400,000	$ 10,400,000