Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Federal net operating loss carryforwards	$ 123,310	$ 129,695
State net operating loss carryforwards	48,902	49,551
Alternative minimum tax and other tax credit carryforwards	11,353	10,988
Stock-based compensation expense	28,978	29,196
Warranty, litigation and other reserves	14,610	14,556
Deferred compensation retirement plans	11,682	11,252
Asset impairment charges	11,441	14,080
Inventory, additional costs capitalized for tax purposes	4,022	3,930
Other, net	1,627	2,063
Total deferred tax assets	255,925	265,311
Valuation allowance	(238,795)	(248,306)
Total deferred tax assets, net of valuation allowance	17,130	17,005
Property, equipment and other assets	5,714	5,753
Discount on notes receivable	4,204	4,204
Deferred revenue	2,974	3,796
Unrealized gain on marketable securities	2,853	1,863
Other, net	1,385	1,389
Total deferred tax liabilities	17,130	17,005
Net deferred tax asset