Related Party Transactions (Details)	3 Months Ended		9 Months Ended		43 Months Ended
	Sep. 30, 2019 USD ($) board_seat	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) board_seat	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) board_seat	Mar. 31, 2016 townhome
Related Party Transaction [Line Items]
Document Period End Date			Sep. 30, 2019
Operating Lease, Expense	$ 300,000		$ 900,000
Lots Remaining To Be Sold	0		0		0
Suwanee Station
Related Party Transaction [Line Items]
Board seats held | board_seat	2		2		2
Board seats available | board_seat	3		3		3
Centre Living
Related Party Transaction [Line Items]
Ownership percentage by parent	50.00%		50.00%		50.00%
Ownership percentage by noncontrolling owners	50.00%		50.00%		50.00%
Percentage of voting interest	51.00%		51.00%		51.00%
Investee | Suwanee Station
Related Party Transaction [Line Items]
Number of real estate properties | townhome						73
Payments of Capital Distribution	$ 0.0	$ 200,000	$ 900,000	$ 900,000	$ 3,300,000
Number of Lots Purchased	0	7	13	18
Lots Purchased, Cost	$ 0.0	$ 300,000	$ 500,000	$ 1,000,000.0
Investee | Suwanee Station | Green Brick Partners, Inc. [Member]
Related Party Transaction [Line Items]
Payments of Capital Distribution	0.0	$ 100,000	500,000	$ 400,000
Investee | Suwanee Station | Parent Company [Member]
Related Party Transaction [Line Items]
Equity Method Investment, Ownership Percentage						50.00%
Investee | Suwanee Station | Affiliated Entity
Related Party Transaction [Line Items]
Equity Method Investment, Ownership Percentage						50.00%
Affiliated Entity | Office Space Lease Agreements | Trophy Signature Homes [Member]
Related Party Transaction [Line Items]
Amounts due to affiliates	0		0		0
Affiliated Entity | Office Space Lease Agreements | GHO Homes [Member]
Related Party Transaction [Line Items]
Operating Lease, Expense			100,000
Amounts due to affiliates	0		0		0
Affiliated Entity | Title Closing Services | GHO Homes [Member]
Related Party Transaction [Line Items]
Amounts due to affiliates	$ 0		$ 0		$ 0