Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Operating Activities:
Net income	$ 53,392	$ 61,163	$ 156,055	$ 117,283
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Stock-based compensation expense			8,500	3,100
Depreciation and amortization			15,406	4,205
Inventory impairments	11,098	4,540	11,848	9,390
Other-than-temporary impairment of marketable securities				211
Net gain on sale of available-for-sale marketable securities				(18,122)
Net gain on marketable equity securities	(3,004)		(3,129)
Gain on sale of metropolitan district bond securities (related party)				(35,847)
Amortization of discount / premiums on marketable debt securities, net			(366)
Deferred income tax expense			4,092	22,795
Net changes in assets and liabilities:
Trade and other receivables			(7,049)	119
Mortgage loans held-for-sale			23,278	48,970
Prepaid and other assets			(12,328)	(11,229)
Accounts payable and accrued liabilities			26,067	15,345
Net cash provided by (used in) operating activities			(59,246)	74,109
Investing Activities:
Purchases of marketable securities			(17,183)	(17,604)
Maturities of marketable securities			50,000
Sales of marketable securities			13,310	83,315
Proceeds from sale of metropolitan district bond securities (related party)				44,253
Purchases of property and equipment			(19,899)	(1,917)
Net cash provided by investing activities			26,228	108,047
Financing Activities:
Payments on mortgage repurchase facility, net			(21,556)	(49,382)
Dividend payments			(50,733)	(38,793)
Payments of deferred financing costs				(2,630)
Proceeds from exercise of stock options			9,859	8,503
Net cash used in financing activities			(62,430)	(82,302)
Net increase (decrease) in cash, cash equivalents and restricted cash			(95,448)	99,854
Cash, cash equivalents and restricted cash:
Beginning of period			514,240	286,687
End of period	418,792	386,541	418,792	386,541
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	418,792	386,541	418,792	386,541
End of period	418,792	386,541	418,792	386,541
Homebuilding Segment [Member]
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Inventory impairments	11,098	4,540	11,848	9,390
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	360,947	351,399	360,947	351,399
Restricted cash	7,866	8,723	7,866	8,723
Financial Services Segment [Member]
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	$ 49,979	$ 26,419	49,979	26,419
Housing Completed or Under Construction [Member]
Net changes in assets and liabilities:
Housing completed or under construction and land under development			(131,657)	(101,997)
Land and Land Under Development [Member]
Net changes in assets and liabilities:
Housing completed or under construction and land under development			$ (149,963)	$ 19,886