Summary of Significant Accounting Policies - New accounting pronouncements (Details) - USD ($) |
3 Months Ended | 6 Months Ended | ||||
|---|---|---|---|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2017 |
Jun. 30, 2018 |
Jun. 30, 2017 |
Jan. 01, 2018 |
Dec. 31, 2017 |
|
| New accounting pronouncements | ||||||
| Revenue | $ 9,038,000 | $ 3,521,000 | $ 17,234,000 | $ 6,378,000 | ||
| Operating loss | (28,877,000) | (23,780,000) | (57,277,000) | (46,001,000) | ||
| Loss before income taxes | (43,743,000) | (20,050,000) | (64,354,000) | (41,601,000) | ||
| Net loss attributable to ordinary shareholders | $ (43,845,000) | $ (20,215,000) | $ (64,583,000) | $ (41,997,000) | ||
| Net loss per ordinary share basic and diluted (in dollars per share) | $ (0.08) | $ (0.04) | $ (0.11) | $ (0.09) | ||
| Deferred revenue | $ 16,722,000 | $ 16,722,000 | $ 38,735,000 | |||
| Total current liabilities | 42,310,000 | 42,310,000 | 74,314,000 | |||
| Total liabilities | 46,197,000 | 46,197,000 | 78,163,000 | |||
| Accumulated deficit | (287,568,000) | (287,568,000) | (231,630,000) | |||
| Total stockholders' equity | 165,102,000 | 165,102,000 | 202,984,000 | |||
| Net loss | (64,583,000) | $ (41,997,000) | ||||
| Decrease in payables and deferred revenue | (24,162,000) | $ (10,125,000) | ||||
| Cumulative effect of adopting ASC 606 | $ 8,645,000 | |||||
| Right-of-use asset | 25,000,000 | 25,000,000 | ||||
| Lease liability | 25,000,000 | 25,000,000 | ||||
| ASU 2014-09 | ||||||
| New accounting pronouncements | ||||||
| Cumulative effect of adopting ASC 606 | $ (8,645,000) | |||||
| ASU 2014-09 | Under previous revenue guidance | ||||||
| New accounting pronouncements | ||||||
| Revenue | 3,267,000 | 12,263,000 | ||||
| Operating loss | (34,648,000) | (62,248,000) | ||||
| Loss before income taxes | (49,514,000) | (69,325,000) | ||||
| Net loss attributable to ordinary shareholders | $ (49,616,000) | $ (69,554.00) | ||||
| Net loss per ordinary share basic and diluted (in dollars per share) | $ (0.09) | $ (0.12) | ||||
| Deferred revenue | $ 30,338,000 | $ 30,338,000 | ||||
| Total current liabilities | 55,926,000 | 55,926,000 | ||||
| Total liabilities | 59,813,000 | 59,813,000 | ||||
| Accumulated deficit | (301,184,000) | (301,184,000) | ||||
| Total stockholders' equity | 151,486,000 | 151,486,000 | ||||
| Net loss | (69,554,000) | |||||
| Decrease in payables and deferred revenue | (19,191,000) | |||||
| ASU 2014-09 | Adjustment | ||||||
| New accounting pronouncements | ||||||
| Revenue | 5,771,000 | 4,971,000 | ||||
| Operating loss | 5,771,000 | 4,971,000 | ||||
| Loss before income taxes | 5,771,000 | 4,971,000 | ||||
| Net loss attributable to ordinary shareholders | 5,771,000 | 4,971.00 | ||||
| Deferred revenue | (13,616,000) | (13,616,000) | ||||
| Total current liabilities | (13,616,000) | (13,616,000) | ||||
| Total liabilities | (13,616,000) | (13,616,000) | ||||
| Accumulated deficit | 13,616,000 | 13,616,000 | ||||
| Total stockholders' equity | $ 13,616,000 | 13,616,000 | ||||
| Net loss | 4,971,000 | |||||
| Decrease in payables and deferred revenue | $ (4,971,000) | |||||