Spin-Off and Other Significant Business Transactions - Additional Information (Details)						12 Months Ended
	Oct. 10, 2025	Jun. 25, 2025 USD ($) Property	May 12, 2025 USD ($)	Feb. 10, 2025 USD ($) Property	Feb. 07, 2025 USD ($) Property $ / shares shares	Dec. 31, 2025 USD ($) Property $ / shares shares	Nov. 26, 2025 shares	Sep. 11, 2025 USD ($)	Aug. 07, 2025 USD ($)
Business Combination [Line Items]
Number of homesites | Property						933
Cash contribution						$ 415,152,000
Common stock par value per share | $ / shares						$ 0.01
Deferred tax liabilities						$ 77,333,000
Deferred tax asset						109,282,000
Earnest Money Deposits						4,000,000
Development guarantee holdbacks						100,000,000
Land banking proceeds to acquire amount						$ 858,938,000
Rausch Land Assets
Business Combination [Line Items]
Number of homesites | Property				25,000
Deferred tax liabilities				$ 116,700,000
Earnest Money Deposits				7,600,000
Cash payment received from acquisition				858,900,000
Option deposits				90,300,000
Development guarantee holdbacks				$ 100,000,000
Landsea Homes | Agreement with New Home Company
Business Combination [Line Items]
Number of homesites | Property		4,186
Land banking proceeds to acquire amount		$ 494,500,000
Acquisition in land assets		522,800,000
Option contract to acquire business		$ 28,300,000
Landsea Homes | Maximum | Agreement with New Home Company
Business Combination [Line Items]
Land banking proceeds to acquire amount			$ 700,000,000
Rausch Coleman Companies, LLC
Business Combination [Line Items]
Percentage of interest acquired				100.00%
Acquisition in land assets				$ 1,158,000,000
Rausch Coleman Companies, LLC | Rausch Land Assets
Business Combination [Line Items]
Cash payment received from acquisition				$ 859,000,000
Class A Common Stock
Business Combination [Line Items]
Common stock par value per share | $ / shares						$ 0.01
Class B Common Stock
Business Combination [Line Items]
Common stock par value per share | $ / shares						$ 0.01
Lennar Class A Common Stock
Business Combination [Line Items]
Percentage of common shares outstanding	20.00%
Shares owned | shares							8,049,594
Millrose Class A Common Stock
Business Combination [Line Items]
Shares owned | shares							33,298,754
2030 Notes | Agreement with New Home Company
Business Combination [Line Items]
Aggregate principal amount									$ 1,250,000,000
Principal amount stated percentage									6.375%
2032 Notes | Agreement with New Home Company
Business Combination [Line Items]
Aggregate principal amount								$ 750,000,000
Principal amount stated percentage								6.25%
Revolving Credit Facility
Business Combination [Line Items]
Commitment amount					$ 1,335,000,000	$ 1,335,000,000
Maturity date						Feb. 07, 2028
Lennar Corporation
Business Combination [Line Items]
Percentage of ownership interest after disposal					20.00%
Spin-Off
Business Combination [Line Items]
Stockholders equity for contributions					$ 5,200,000,000
Spin-Off | Lennar Corporation
Business Combination [Line Items]
Percentage of ownership interest sold					80.00%
Land assets					$ 5,500,000,000
Number of homesites | Property					87,000
Cash					$ 1,000,000,000
Cash deposits					585,000,000
Cash contribution					415,000,000
Common stock issued, Spin-Off					1,300,000
Liabilities for seller notes					19,000,000
Liabilities for prepaid due diligence costs					77,900,000
Deferred tax asset					59,800,000
Stockholders equity for contributions					5,900,000,000
Spin-Off related costs					$ 77,900,000
Spin-Off | Lennar Corporation | Class A Common Stock
Business Combination [Line Items]
Distribution of common stock | shares					120,983,633	120,983,633
Common stock par value per share | $ / shares					$ 0.01
Common stock issued, Spin-Off					$ 300,000
Retained shares | shares					33,200,053	33,200,053
Spin-Off | Lennar Corporation | Class B Common Stock
Business Combination [Line Items]
Distribution of common stock | shares					11,819,811	11,819,811
Common stock par value per share | $ / shares					$ 0.01
Spin-Off | Lennar Corporation | Revolving Credit Facility
Business Combination [Line Items]
Commitment amount					$ 1,335,000,000
Maturity date					Feb. 07, 2028