Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Deferred Tax Liability Not Recognized [Line Items]
Federal net operating loss carryforwards	$ 133,796	$ 133,454
State net operating loss carryforwards	52,576	53,350
Stock-based compensation expense	28,944	26,771
Accrued liabilities	26,391	29,600
Asset impairment charges	20,613	31,137
Alternative minimum tax and other tax credit carryforwards	10,726	10,296
Inventory, additional costs capitalized for tax	3,833	3,466
Unrealized loss on marketable securities		2,787
Other	1,606	1,522
Total deferred tax assets	278,485	292,383
Valuation allowance	(263,561)	(281,178)
Total deferred tax assets, net of valuation allowance	14,924	11,205
Property, equipment and other assets	4,440	706
Deferred revenue	3,445	5,589
Unrealized gain on marketable securities	1,426
Inventory, additional costs capitalized for financial statement purposes	482	542
Accrued liabilities	758	32
Other, net	4,373	4,336
Total deferred tax liabilities	14,924	11,205
Net deferred tax asset