Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash Flows From Operating Activities
Net loss	$ (19,254)	$ (195,476)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	40,048	8,511
Stock-based compensation	34,582	23,254
Amortization of Department of Energy (DOE) loan origination costs	5,558
Inventory write-downs	5,589	3,678
Amortization of discount on 1.50% convertible senior notes	1,582
Change in fair value of DOE warrant liability	(10,692)	(309)
Discounts and premiums on short-term marketable securities		56
Other	600	1,020
Changes in operating assets and liabilities
Accounts receivable	(86,702)	(1,483)
Inventories and operating lease vehicles	(129,246)	(18,438)
Prepaid expenses and other current assets	(3,444)	2,580
Other assets	304	(79)
Accounts payable	(6,421)	3,473
Accrued liabilities	14,951	2,878
Deferred revenue	93,110	(114)
Customer deposits	(5,100)	41,686
Other long-term liabilities	90,421	1,199
Net cash provided by (used in) operating activities	25,886	(127,564)
Cash Flows From Investing Activities
Purchases of property and equipment, excluding capital leases	(98,242)	(112,777)
Withdrawals out of our dedicated DOE accounts, net	14,752	8,218
Decrease (increase) in other restricted cash	1,080	(2,608)
Purchases of marketable securities		(14,992)
Maturities of short-term marketable securities		40,000
Net cash used in investing activities	(82,410)	(82,159)
Cash Flows From Financing Activities
Proceeds from 1.50% convertible senior notes	660,000
Proceeds from issuance of warrants	120,318
Purchase of convertible note hedges	(177,540)
Proceeds from issuance of common stock in public offering	360,000
Proceeds from issuance of common stock in private placement	55,000
Common stock and 1.50% convertible senior notes issuance costs	(16,207)
Principal payments on DOE loans	(452,337)
Proceeds from DOE loans		155,541
Proceeds from exercise of stock options and other stock issuances	55,091	10,391
Principal payments on capital leases and other debt	(3,634)	(921)
Net cash provided by financing activities	600,691	165,011
Net increase (decrease) in cash and cash equivalents	544,167	(44,712)
Cash and cash equivalents at beginning of period	201,890	255,266
Cash and cash equivalents at end of period	746,057	210,554
Supplemental disclosure of noncash investing activities:
Acquisition of property and equipment included in accounts payable and accrued liabilities	$ 20,593	$ 30,167