Employee Benefit Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension plans for Swedish employees [Member]
Employee Benefit Plans (Textual)
Defined benefit plan contribution, amount	$ 368,000	$ 398,000	$ 306,000
Pension plans for Swedish employees [Member] | Minimum [Member]
Employee Benefit Plans (Textual)
Defined benefit plan contribution, percentage	5.00%	5.00%	5.00%
Pension plans for Swedish employees [Member] | Maximum [Member]
Employee Benefit Plans (Textual)
Defined benefit plan contribution, percentage	15.00%	15.00%	15.00%
U.S. Employee 401K Pension Plan [Member]
Employee Benefit Plans (Textual)
Defined benefit plan contribution, amount	$ 6,000	$ 33,000	$ 89,000
Matching contributions by employer	6.00%	6.00%	6.00%
Pension Plans for Taiwan Employees [Member]
Employee Benefit Plans (Textual)
Defined benefit plan contribution, amount	$ 4,000	$ 10,000	$ 10,000
Defined benefit plan contribution, percentage	6.00%	6.00%	6.00%