Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 59,824	$ 73,933
Investments	152,032	131,149
Prepaid expenses and other current assets	5,247	2,528
Total current assets	217,103	207,610
Property and equipment, net	26,985	7,751
Long-term investments	60,589
Restricted cash	1,540	1,539
Total assets	306,217	216,900
Current liabilities:
Accounts payable	4,454	5,397
Accrued expenses and other current liabilities	10,865	5,523
Deferred revenue - related party	12,012
Total current liabilities	27,331	10,920
Lease incentive obligation	9,119	586
Deferred revenue, net of current portion - related party	102,371
Total liabilities	138,821	11,506
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; 10,000,000 shares authorized at June 30, 2016 and December 31, 2015; no shares issued and outstanding at June 30, 2016 and December 31, 2015
Common stock, $0.001 par value; 200,000,000 shares authorized at June 30, 2016 and December 31, 2015; 39,859,155 and 39,082,017 shares issued and outstanding at June 30, 2016 and December 31, 2015, respectively	40	39
Additional paid-in capital	297,502	287,937
Accumulated other comprehensive income	83	30
Accumulated deficit	(130,229)	(82,612)
Total stockholders’ equity	167,396	205,394
Total liabilities and stockholders’ equity	$ 306,217	$ 216,900