Nature of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands							1 Months Ended								3 Months Ended								12 Months Ended
	Dec. 02, 2019	Oct. 29, 2019	Oct. 15, 2019	Mar. 08, 2018	Apr. 12, 2017	Apr. 03, 2017	Jan. 31, 2020	Dec. 31, 2019	Nov. 30, 2019	Sep. 30, 2019	Apr. 30, 2019	Mar. 31, 2019	Nov. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Liquidity
Net loss attributable to common shareholders															$ 18,288	$ 18,155	$ 18,070	$ 31,004	$ 16,860	$ 15,578	$ 25,881	$ 19,848	$ 85,517	$ 78,167	$ 130,178
Accumulated deficit								$ 1,345,807							1,345,807				1,260,290				1,345,807	1,260,290
Net cash used in operating activities																							51,522	57,617	60,182
Net loss attributable to the Company																							(85,465)	(78,115)	(127,080)
Net outflows from fluctuations in working capital and other assets and liabilities																							7,100
Non-cash charges																							41,000
Cash and cash equivalents								139,496							139,496				38,602				139,496	38,602
Net working capital								162,500							162,500				$ 9,200				162,500	9,200
Net cash used in investing activities																							(14,244)	(19,572)	(44,363)
Net cash provided by financing activities																							325,060	119,344	71,616
Proceeds from public offerings, net of transaction costs												$ 23,500											158,428	7,195	22,992
Value of shares issued																							158,429	7,016	22,992
Proceeds from issuance of preferred stock and warrants, net of transaction costs																							14,089	30,934	17,636
Increase in cash flows from new finance obligations																							83,700
Proceeds from issuance of debt																							39,052	95,856
Principal payments on long-term debt																							24,827	16,190	12,292
Proceeds from borrowing of long-term debt, net of transaction costs																							119,186		20,147
Principal amount														$ 100,000								100,000
Obligation, net of interest accretion										$ 48,000						48,000
Purchase of capped call and common stock forward																								43,500
Remaining lease payments								227,200							227,200								227,200
Security on lease								234,500							234,500								234,500
Letter of credit								103,400							$ 103,400								103,400
Cash Collateral for Borrowed Securities										15,900						15,900
Repayments of finance obligations																							61,713	$ 31,264	18,632
Payments for redemption of preferred stock																							4,040		$ 3,700
Number of common stock sold												10,000,000
Share price (in dollars per share)												$ 2.35						$ 2.35
Number of preferred shares that had been converted to common stock															30,962
Proceeds from Stock Options Exercised																							1,200
Warrants issued in December 2016
Liquidity
Shares of common stock that can be purchased from warrants issued (in shares)					5,250,750
Per share price of shares of common stock					$ 2.69
Proceeds from exercise of warrants, net of transaction costs					$ 15,100
Proceeds from Stock Options Exercised			$ 14,100
Additional Master Lease Agreements
Liquidity
Remaining lease payments								93,200							$ 93,200								93,200
Secured term loan facility
Liquidity
Proceeds from borrowing of long-term debt									$ 20,000
Wells Fargo
Liquidity
Remaining lease payments								112,800							112,800								112,800
Letter of credit								30,700							30,700								30,700
Loan and security agreement | Generate Lending, LLC
Liquidity
Repayments of finance obligations												$ 17,600
Loan and security agreement | Generate Lending, LLC | Secured term loan facility
Liquidity
Proceeds from borrowing of long-term debt											$ 15,000	85,000
Outstanding balance								112,700							112,700								112,700
Interest rate (as a percent)									12.00%
Termination of certain equipment leases												$ 50,300
Convertible Senior Notes
Liquidity
Principal amount										$ 40,000				$ 100,000		$ 40,000						$ 100,000
Interest rate (as a percent)										7.50%				5.50%		7.50%						5.50%
$40M Convertible Senior Note
Liquidity
Proceeds from issuance of debt										$ 39,100
Outstanding balance								39,600							39,600								39,600
Principal amount								$ 48,000		$ 40,000					$ 48,000	$ 40,000							$ 48,000
Interest rate (as a percent)										7.50%						7.50%
Obligation, net of interest accretion										$ 48,000						$ 48,000
Share price (in dollars per share)								$ 3.16							$ 3.16								$ 3.16
$100M Convertible Senior Notes
Liquidity
Proceeds from issuance of debt				$ 52,356										$ 95,900
Outstanding balance								$ 70,600							$ 70,600								$ 70,600
Principal amount				100,000				$ 100,000						$ 100,000	$ 100,000							$ 100,000	$ 100,000
Interest rate (as a percent)														5.50%								5.50%
Purchase of capped call and common stock forward				$ 43,500										$ 43,500
Share price (in dollars per share)								$ 3.16							$ 3.16								$ 3.16
Series E Preferred Stock
Liquidity
Number of redeemed shares							4,038									4,038
Amount of redeemed shares																$ 4,000
Number of preferred shares that had been converted to common stock							500
Series E Redeemable Convertible Preferred Stock
Liquidity
Shares issued (in shares)													35,000
Redeemable stock issued, stated value (in dollars per share)								$ 0.01					$ 0.01		0.01				$ 0.01				$ 0.01	$ 0.01
Number of shares of common stock issued on conversion of preferred stock							216,000
Aggregate proceeds from issuance of preferred stock													$ 30,900
At Market Issuance Sales Agreement
Liquidity
Proceeds from public offerings, net of transaction costs																							$ 14,500
Value of shares issued	$ 46,800	$ 46,800
Number of common stock sold																							6,300,000
Redeemable stock issued, stated value (in dollars per share)						$ 0.01
Authorized amount						$ 75,000
Public Offerings
Liquidity
Proceeds from public offerings, net of transaction costs								$ 120,400															$ 120,400
Number of common stock sold								46,000,000				10,000,000											46,000,000
Share price (in dollars per share)								$ 2.75				$ 2.35			$ 2.75			$ 2.35					$ 2.75
Number of shares of common stock issued on conversion of preferred stock															13,800,000