Deferred tax assets and liabilities
| As of December 31, | ||||||||||||
| 2015 | 2016 | 2017 | ||||||||||
| $ in thousands | ||||||||||||
|
Credits and net operating loss carryforwards |
37,719 | 41,985 | 51,640 | |||||||||
|
Pension commitments |
164 | 193 | 548 | |||||||||
|
Leases |
(126 | ) | (54 | ) | (12 | ) | ||||||
|
Impairment of assets |
16 | 14 | 10 | |||||||||
|
Other |
284 | 894 | 604 | |||||||||
|
Valuation allowance on deferred tax assets |
(38,057 | ) | (43,032 | ) | (52,790 | ) | ||||||
|
|
|
|
|
|
|
|||||||
| Total | — | — | — | |||||||||
|
|
|
|
|
|
|
|||||||