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 ($)	Dec. 31, 2018 USD ($)
Payments to acquire businesses, gross						$ 10,400,000	$ 83,251,000	$ 163,724,000
Goodwill impairment				$ 20,200,000		0	20,190,000	0
Escrow deposit						38,400,000	6,100,000
Restricted cash						54,477,000	50,030,000
Finite-Lived Intangible Assets, Net						78,000,000	94,500,000
Intangible assets, accumulated amortization						76,600,000	224,100,000
Intangible assets amortization expense						16,502,000	19,685,000	14,200,000
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months						11,100,000
Future Amortization Expense, Year Two						10,500,000
Future Amortization Expense, Year Three						10,000,000
Future Amortization Expense, Year Four						9,300,000
Future Amortization Expense, Year Five						8,900,000
Property and equipment, net						149,151,000	131,744,000
Property and equipment, accumulated depreciation						228,500,000	228,800,000
Depreciation Expense						53,500,000	46,400,000	39,800,000
Advertising Expense						47,200,000	40,300,000	53,900,000
Employee benefit plan company contributions						23,400,000	20,400,000	19,100,000
Customer deposits						844,785,000	449,474,000
Capitalized contract costs						$ 44,300,000	$ 38,500,000
Number of VIEs requiring consolidation						0	0
Residential mortgage loans available-for-sale						$ 947,139,000	$ 564,979,000
Residential mortgage loans available-for-sale aggregate outstanding principal balance						924,500,000	539,100,000
Net gains from the sale of mortgages						$ 251,300,000	247,300,000	129,400,000
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
Stockholders' Equity Attributable to Parent						$ 7,489,515,000	6,569,989,000	5,458,180,000	$ 4,817,782,000
Cumulative Effect, Period of Adoption, Adjustment
Stockholders' Equity Attributable to Parent								(735,000)
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						$ 10,000,000	9,200,000	9,700,000
Interest rate lock commitments
Derivative, Notional Amount						337,900,000	367,200,000
Forward contracts
Derivative, Notional Amount						903,000,000	686,400,000
Whole loan commitments
Derivative, Notional Amount						310,000,000	169,600,000
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
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
Innovative Construction Group [Member]
Business combination, consideration transferred	$ 104,000,000
Payments to acquire businesses, gross	83,300,000					$ 10,400,000
Goodwill	48,700,000
Innovative Construction Group [Member] | Trade Names [Member]
Finite-lived intangible assets acquired	$ 1,800,000
Weighted average useful life (in years)	5 years
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
JW Homes (Wieland) [Member]
Goodwill							68,900,000
Restricted stock [Member]
Share-based compensation vesting period						3 years
Retained Earnings
Stockholders' Equity Attributable to Parent						$ 4,196,276,000	3,306,057,000	2,220,574,000	$ 1,613,929,000
Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment
Insurance Receivables, Contract Assets, and Vendor Rebate Receivables recognized						$ 208,400,000	$ 176,200,000
Accounting Standards Update 2016-13 [Member] | Retained Earnings | Cumulative Effect, Period of Adoption, Adjustment
Stockholders' Equity Attributable to Parent								$ (735,000)
Forecast [Member] | Innovative Construction Group [Member]
Payments to acquire businesses, gross					$ 10,400,000