Income Taxes Net deferred tax asset (liability) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets [Abstract]
Deferred Tax Assets, Tax Deferred Expense, Other	$ 117,133	$ 220,823
Non-deductible reserves and other	78,271	132,597
Inventory valuation reserves	202,791	359,964
Net operating loss (NOL) carryforwards:
Federal	41,282	187,817
State	248,224	224,316
Alternative minimum tax credits	54,965	53,917
Energy credit and charitable contribution carryforward	41,763	45,673
Deferred Tax Assets, Gross	784,429	1,225,107
Deferred Tax Liabilities [Abstract]
Capitalized items, including real estate basis differences, deducted for tax, net	(17,895)	(13,054)
Deferred Tax Liability, deferral of profit on home sales	(34,769)	(69,391)
Trademarks and tradenames	(17,860)	(28,391)
Deferred Tax Liabilities, Gross	(70,524)	(110,836)
Valuation allowance	(68,610)	(64,863)
Net deferred tax asset (liability)	$ 645,295	$ 1,049,408