Restatement (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended						6 Months Ended	9 Months Ended		12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2012	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating activities:
Net income (loss)										$ 18,213	$ 5,518	$ (5,350)
Net loss from discontinued operations		23	11	15	149	24	26	49	(37)	56	112	(8,816)
Net income (loss) from continuing operations		(5,190)	(2,242)	29,316	(2,747)	6,093	27,074	21,884	8,377	18,269	5,630	(14,166)
Adjustments to reconcile net income (loss) from continuing operations to net cash used in operating activities of continuing operations:
Depreciation and amortization				328			693	1,420	1,017	2,195	1,348	1,747
Share-based compensation				241			442	746	1,058	1,068	1,347	1,091
Loss on extinguishment of debt									(15,349)	0	(15,349)	3,384
(Amortization) accretion of debt net premium/discount from convertible notes				73			73	73	(140)	81	(140)	825
Loss on net change in fair value of derivative assets and liabilities		0	(139)	706	(136)	(290)	567	567	1,005	548	869	145
Non-cash restructuring charges				2			16	17	377	20	532	0
Non-cash income tax benefit	200	(132)	(76)	814	(368)	0	738	606		226	(368)	(9,748)
Changes in operating assets and liabilities:
Accounts receivable				2,306			1,354	4,121	(1,273)	794	(4,663)	(39)
Inventories				(623)			840	1,306	(632)	1,012	(1,007)	(2,730)
Other assets				189			203	35	278	110	1,165	2,894
Accounts payable and accrued liabilities				(2,153)			(3,944)	(5,184)	(6,972)	(357)	(2,929)	8,020
Deferred revenue				(1,815)			(2,291)	(2,545)	2,986	(2,471)	3,175	309
Net cash used in operating activities of continuing operations				(2,708)			(6,251)	(8,838)	(9,268)	(10,009)	(10,390)	(8,977)
Investing activities:
Purchases of property and equipment, net				(3,636)			(7,228)	(9,439)	(3,232)	(10,046)	(5,396)	(1,554)
Restricted cash				2,500			2,500	4,100		5,700	(3,200)	5,400
Net cash provided by (used in) investing activities of continuing operations				32,597			26,455	25,844	(3,232)	26,837	(8,596)	99,872
Financing activities:
Principal payments on debt obligations				0			(34,851)	(34,851)		(34,851)	(38,645)	(20,568)
Proceeds from sale of common stock and warrants				6			447	481		501	2	15
Proceeds from issuance of debt, net of issuance costs										24,063	(355)	0
Net cash used in financing activities of continuing operations				6			(34,423)	(31,553)	(38,645)	(10,414)	(38,998)	(20,553)
Cash used in discontinued operations:
Net cash used in operating activities of discontinued operations				(95)			(183)	(274)	(1,112)	(298)	(1,186)	(32,490)
Net cash used in discontinued operations				(95)			(183)	(274)	(1,112)	(298)	(1,186)	(7,257)
Net increase (decrease) in cash and cash equivalents				29,800			(14,402)	(14,821)	(52,257)	6,116	(59,170)	63,085
Cash and cash equivalents at beginning of year	13,938	14,357	58,559	28,759	35,672	44,620	28,759	28,759	87,929	28,759	87,929	24,844
Cash and cash equivalents at end of year	34,875	13,938	14,357	58,559	28,759	35,672	14,357	13,938	35,672	34,875	28,759	87,929
Supplemental disclosure of cash flow information:
Interest paid				0			1,038	1,513	2,428	1,986	3,386	4,090
Supplemental disclosure of non-cash activities:
Property acquired under lease financing obligation											7,391
Previously Reported [Member]
Operating activities:
Net income (loss)											5,127
Net loss from discontinued operations		23	11	15	149	24	26	49	(37)		112
Net income (loss) from continuing operations		(5,234)	(2,468)	30,137	(2,867)	5,822	27,669	22,435	8,106		5,239
Adjustments to reconcile net income (loss) from continuing operations to net cash used in operating activities of continuing operations:
Depreciation and amortization				328			618	1,120	1,017		1,348
Share-based compensation				241			442	746	1,058		1,347
Loss on extinguishment of debt									(15,349)		(15,349)
(Amortization) accretion of debt net premium/discount from convertible notes				73			73	73	(140)		(140)
Loss on net change in fair value of derivative assets and liabilities		0	(232)	324	(41)	(290)	92	92	1,005		964
Non-cash restructuring charges				2			16	17	377		532
Non-cash income tax benefit		(147)	(87)	829	(368)	0	742	595			(368)
Changes in operating assets and liabilities:
Accounts receivable				2,306			1,354	4,121	(1,273)		(4,663)
Inventories				(623)			840	1,306	(632)		(1,007)
Other assets				(578)			(447)	(548)	278		785
Accounts payable and accrued liabilities				(2,244)			(4,248)	(6,204)	(6,017)		(1,464)
Deferred revenue				(1,815)			(2,291)	(2,545)	2,986		3,175
Net cash used in operating activities of continuing operations				(3,330)			(7,160)	(10,665)	(8,584)		(9,601)
Investing activities:
Purchases of property and equipment, net				(3,014)			(6,338)	(7,684)	(3,916)		(6,540)
Restricted cash				2,500			2,500	4,100			(3,200)
Net cash provided by (used in) investing activities of continuing operations				33,219			27,345	27,599	(3,916)		(9,740)
Financing activities:
Principal payments on debt obligations				0			(34,851)	(34,851)			(38,645)
Proceeds from sale of common stock and warrants				6			447	481			2
Proceeds from issuance of debt, net of issuance costs											0
Net cash used in financing activities of continuing operations				6			(34,404)	(31,481)	(38,645)		(38,643)
Cash used in discontinued operations:
Net cash used in operating activities of discontinued operations				(95)			(183)	(274)	(1,112)		(1,186)
Net cash used in discontinued operations				(95)			(183)	(274)	(1,112)		(1,186)
Net increase (decrease) in cash and cash equivalents				29,800			(14,402)	(14,821)	(52,257)		(59,170)
Cash and cash equivalents at beginning of year		14,357	58,559	28,759	35,672	44,620	28,759	28,759	87,929	28,759	87,929
Cash and cash equivalents at end of year		13,938	14,357	58,559	28,759	35,672	14,357	13,938	35,672		28,759
Supplemental disclosure of cash flow information:
Interest paid				0			958	958	2,428		3,386
Supplemental disclosure of non-cash activities:
Property acquired under lease financing obligation											0
Adjustments [Member]
Operating activities:
Net income (loss)											391
Net loss from discontinued operations		0	0	0	0	0	0	0	0		0
Net income (loss) from continuing operations		44	226	(821)	120	271	(595)	(551)	271		391
Adjustments to reconcile net income (loss) from continuing operations to net cash used in operating activities of continuing operations:
Depreciation and amortization				0			75	300	0		0
Share-based compensation				0			0	0	0		0
Loss on extinguishment of debt									0		0
(Amortization) accretion of debt net premium/discount from convertible notes				0			0	0	0		0
Loss on net change in fair value of derivative assets and liabilities		0	93	382	(95)	0	475	475	0		(95)
Non-cash restructuring charges				0			0	0	0		0
Non-cash income tax benefit		15	11	(15)	0	0	(4)	11			0
Changes in operating assets and liabilities:
Accounts receivable				0			0	0	0		0
Inventories				0			0	0	0		0
Other assets				767			650	583	0		380
Accounts payable and accrued liabilities				91			304	1,020	(955)		(1,465)
Deferred revenue				0			0	0	0		0
Net cash used in operating activities of continuing operations				622			909	1,827	(684)		(789)
Investing activities:
Purchases of property and equipment, net				(622)			(890)	(1,755)	684		1,144
Restricted cash				0			0	0			0
Net cash provided by (used in) investing activities of continuing operations				(622)			(890)	(1,755)	684		1,144
Financing activities:
Principal payments on debt obligations				0			0	0			0
Proceeds from sale of common stock and warrants				0			0	0			0
Proceeds from issuance of debt, net of issuance costs											(355)
Net cash used in financing activities of continuing operations				0			(19)	(72)	0		(355)
Cash used in discontinued operations:
Net cash used in operating activities of discontinued operations				0			0	0	0		0
Net cash used in discontinued operations				0			0	0	0		0
Net increase (decrease) in cash and cash equivalents				0			0	0	0		0
Cash and cash equivalents at beginning of year		0	0	0	0	0	0	0	0	0	0
Cash and cash equivalents at end of year		0	0	0	0	0	0	0	0		0
Supplemental disclosure of cash flow information:
Interest paid				0			80	555	0		0
Supplemental disclosure of non-cash activities:
Property acquired under lease financing obligation											$ 7,391