Condensed Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net income	$ 87,507,000	$ 46,754,000
Depreciation, Depletion and Amortization	2,461,000	2,443,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Share-based compensation expense	1,958,000	2,035,000
Earnest Money Deposits and Pre-acquisition Costs Written-Off	1,490,000	520,000
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	210,000	(1,749,000)
Deferred income taxes, net	(115,000)	706,000
Income (Loss) from Equity Method Investments	(13,038,000)	(7,565,000)
Distributions of income from unconsolidated entities	7,444,000	3,390,000
Changes in operating assets and liabilities:
Increase in receivables	(931,000)	(4,668,000)
Increase in inventory	(25,263,000)	(71,392,000)
(Increase) decrease in earnest money deposits	(9,067,000)	860,000
Increase in other assets	(6,951,000)	(623,000)
(Decrease) increase in accounts payable	6,917,000	(8,599,000)
Increase in accrued expenses	25,191,000	2,141,000
Increase (Decrease) in Contract with Customer, Liability	(5,385,000)	4,856,000
Net cash provided by (used in) operating activities	64,097,000	(21,239,000)
Cash flows from investing activities:
Purchase of property and equipment	(1,707,000)	(1,838,000)
Net cash used in investing activities	(12,054,000)	(1,838,000)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Borrowings from lines of credit	217,500,000	165,500,000
Proceeds from Unsecured Notes Payable	37,500,000	75,000,000
Repayments of Lines of Credit	289,000,000	201,500,000
Payment, Tax Withholding, Share-based Payment Arrangement	592,000	544,000
Payments for Repurchase of Common Stock	0	2,186,000
Contributions of LLC Members	400,000	0
Payments to Noncontrolling Interests	5,251,000	10,993,000
Net cash (used in) provided by financing activities	(38,879,000)	22,554,000
Net increase (decrease) in cash and cash equivalents and restricted cash	13,164,000	(523,000)
Cash and cash equivalents, beginning of period		38,315,000
Restricted cash, beginning of period	4,416,000	3,440,000
Cash and cash equivalents and restricted cash, beginning of period	37,685,000	41,755,000
Cash and cash equivalents, end of period		35,123,000
Restricted cash, end of period	10,580,000	6,109,000
Cash and cash equivalents and restricted cash, end of period	50,849,000	41,232,000
Supplemental Cash Flow Information [Abstract]
Interest Paid, Excluding Capitalized Interest, Operating Activities	0	0
Income Taxes Paid, Net	10,181,000	14,313,000
Earnest Money Deposits and Pre-acquisition Costs Written-Off	1,490,000	520,000
Proceeds from Notes Payable	10,715,000	0
Repayments of Notes Payable	(8,584,000)	0
Payments of Debt Issuance Costs	(62,000)	(1,682,000)
Payment for Contingent Consideration Liability, Financing Activities	0	(514,000)
Payments for Repurchase of Redeemable Noncontrolling Interest	(1,505,000)	(527,000)
Payment for Contingent Consideration Liability, Operating Activities	(5,267,000)	(1,332,000)
Payments to Acquire Equity Method Investments	$ 10,347,000	$ 0