Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 197,762	$ 107,721
Accounts receivable, net of allowances of $3,030 and $2,600 at December 31, 2017 and 2016, respectively (includes related party receivables of $169 and $393 at December 31, 2017 and 2016, respectively)	39,169	36,867
Prepaid expenses	5,475	6,044
Other current assets	1,145	2,278
Total current assets	243,551	152,910
Property and equipment, net	70,710	66,941
Goodwill	53,270	53,270
Intangible assets, net	15,912	19,774
Other assets	1,391	1,553
Total assets	384,834	294,448
Current liabilities
Accounts payable (includes related party payables of $3,200 and $2,925 at December 31, 2017 and 2016, respectively)	18,620	13,827
Accrued employee expenses	6,568	8,951
Accrued expenses and other current liabilities (includes related party accrued expenses of $52 and $992 at December 31, 2017 and 2016, respectively)	12,790	12,583
Total current liabilities	37,978	35,361
Deferred tax liabilities	812	2,994
Lease financing obligation, net of current portion	29,129	28,833
Other liabilities	3,797	2,679
Total liabilities	71,716	69,867
Commitments and contingencies
Stockholders’ Equity
Preferred stock — $0.0001 par value; 20,000,000 shares authorized at December 31, 2017 and 2016, respectively; no shares issued and outstanding at December 31, 2017 and 2016	0	0
Common stock — $0.0001 par value; 1,000,000,000 shares authorized at December 31, 2017 and 2016, respectively; 100,428,656 and 86,159,527 shares issued and outstanding at December 31, 2017 and 2016, respectively	10	9
Additional paid-in capital	664,192	542,807
Accumulated deficit	(351,084)	(318,235)
Total stockholders’ equity	313,118	224,581
Total liabilities and stockholders’ equity	$ 384,834	$ 294,448