Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 24,828	$ 46,014
Restricted cash	13,898	11,219
Accounts receivable	15,331	11,923
Inventory	48,776	29,940
Prepaid expenses and other current assets	16,774	11,837
Total current assets	119,607	110,933
Restricted cash	29,329	43,403
Property, plant, and equipment, net	10,414	8,246
Leased property, net	87,065	54,060
Goodwill	9,445	8,291
Intangible assets, net	3,785	3,933
Other assets	11,165	11,966
Total assets	270,810	240,832
Current liabilities:
Accounts payable	42,362	32,112
Accrued expenses	10,595	8,519
Accrual for loss contracts related to service		752
Deferred revenue	8,630	5,736
Finance obligations	34,506	14,787
Current portion of long-term debt	18,762	2,964
Other current liabilities	866	1,615
Total current liabilities	115,721	66,485
Deferred revenue	25,809	17,413
Common stock warrant liability	4,391	11,387
Finance obligations	37,069	29,767
Long-term debt	13,371	20,829
Other liabilities	94	241
Total liabilities	196,455	146,122
Stockholders' equity:
Common stock, $0.01 par value per share; 750,000,000 and 450,000,000 shares authorized at December 31, 2017 and 2016, respectively; Issued (including shares in treasury): 229,073,517 at December 31, 2017 and 191,723,974 at December 31, 2016	2,291	1,917
Additional paid-in capital	1,250,899	1,137,482
Accumulated other comprehensive income	2,194	247
Accumulated deficit	(1,178,636)	(1,051,467)
Less common stock in treasury: 587,151 at December 31, 2017 and 582,328 at December 31, 2016	(3,102)	(3,091)
Total stockholders' equity	73,646	85,088
Total liabilities, redeemable preferred stock, and stockholders' equity	270,810	240,832
Series C Redeemable Convertible Preferred Stock
Redeemable preferred stock
Redeemable preferred stock	$ 709	1,153
Series D Redeemable Convertible Preferred Stock
Redeemable preferred stock
Redeemable preferred stock		$ 8,469