Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 39,336	$ 38,602
Restricted cash	19,297	17,399
Accounts receivable	32,062	37,347
Inventory	65,474	47,910
Prepaid expenses and other current assets	10,296	14,357
Total current assets	166,465	155,615
Restricted cash	50,598	54,152
Property, plant, and equipment, net of accumulated depreciation of $15,125 and $14,403, respectively	13,615	12,869
Leased property, net	141,889	146,751
Goodwill	8,886	9,023
Intangible assets, net	3,677	3,890
Other assets	11,069	8,026
Total assets	396,199	390,326
Current liabilities:
Accounts payable	31,688	34,824
Accrued expenses	6,509	7,864
Deferred revenue	11,736	12,055
Finance obligations	23,997	74,264
Current portion of long-term debt	12,559	16,803
Other current liabilities	2,271	560
Total current liabilities	88,760	146,370
Deferred revenue	25,835	28,021
Common stock warrant liability	2,231	105
Finance obligations	111,195	118,076
Convertible senior notes, net	65,025	63,247
Long-term debt	72,676	133
Other liabilities	17	18
Total liabilities	365,739	355,970
Stockholders' (deficit) equity:
Common stock, $0.01 par value per share; 750,000,000 shares authorized; Issued (including shares in treasury): 244,537,235 at March 31, 2019 and 234,160,661 at December 31, 2018	2,445	2,342
Additional paid-in capital	1,319,879	1,289,714
Accumulated other comprehensive income	1,374	1,584
Accumulated deficit	(1,294,241)	(1,260,290)
Less common stock in treasury: 15,002,663 at March 31, 2019 and December 31, 2018	(30,637)	(30,637)
Total stockholders' (deficit) equity	(1,180)	2,713
Total liabilities, redeemable preferred stock, and stockholders' (deficit) equity	396,199	390,326
Series C Redeemable Convertible Preferred Stock
Redeemable preferred stock:
Redeemable preferred stock	709	709
Series E Redeemable Convertible Preferred Stock
Redeemable preferred stock:
Redeemable preferred stock	$ 30,931	$ 30,934