Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Activities:
Net income	$ 210,780	$ 141,835	$ 103,211
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Stock-based compensation expense	14,017	5,857	7,477
Depreciation and amortization	21,326	5,321	5,132
Inventory Write-down	21,850	10,010	10,173
Other-than-temporary impairment of marketable securities		286	1,443
Net gain on sale of available-for-sale marketable securities		(18,122)	(1,074)
Net loss on marketable equity securities	3,745
Gain on sale of metropolitan district bond securities (related party)		(35,847)
Amortization of discount / premiums on marketable debt securities	(366)
Deferred income tax expense	3,729	44,787	16,145
Net changes in assets and liabilities:
Trade and other receivables	(4,638)	(13,763)	(20,424)
Mortgage loans held-for-sale	(11,097)	660	(23,104)
Prepaid expenses and other assets	(245)	(13,121)	(1,036)
Accounts payable and accrued liabilities	49,325	22,320	21,905
Net cash provided by (used in) operating activities	(7,906)	70,506	115,945
Investing Activities:
Purchases of marketable securities	(18,850)	(67,239)	(48,050)
Maturities of marketable securities	50,000
Sales of marketable securities	16,230	83,315	61,736
Proceeds from sale of metropolitan district bond securities (related party)		44,253
Purchases of property and equipment	(27,166)	(2,539)	(4,468)
Net cash provided by investing activities	20,214	57,790	9,218
Financing Activities:
Advances (payments) on mortgage repurchase facility, net	4,475	(2,145)	25,874
Proceeds from issuance of senior notes		146,463
Dividend payments	(67,718)	(51,897)	(49,088)
Payments of deferred financing costs	(3,026)	(2,665)
Proceeds from exercise of stock options	9,860	9,501
Net cash provided by (used in) financing activities	(56,409)	99,257	(23,214)
Net increase (decrease) in cash and cash equivalents	(44,101)	227,553	101,949
Cash and cash equivalents:
Beginning of year	514,240	286,687	184,738
End of year	470,139	514,240	286,687
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	470,139	514,240	286,687
End of year	470,139	514,240	286,687
Homebuilding Segment [Member]
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Inventory Write-down	21,850	10,010	10,173
Other-than-temporary impairment of marketable securities		51
Net gain on sale of available-for-sale marketable securities		(17,775)	(979)
Gain on sale of metropolitan district bond securities (related party)		(35,847)
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	414,724	472,957	259,087
Restricted cash	6,363	8,812	3,778
Financial Services Segment [Member]
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Net gain on sale of available-for-sale marketable securities	3,745
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	49,052	32,471	23,822
Housing Completed or Under Construction [Member]
Net changes in assets and liabilities:
Housing completed or under construction and land under development	(12,082)	(69,548)	(128,525)
Land and Land Under Development [Member]
Net changes in assets and liabilities:
Housing completed or under construction and land under development	$ (304,250)	$ (10,169)	$ 124,622