Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2018 USD ($) Contract	Dec. 31, 2017 USD ($) Contract	Dec. 31, 2016 USD ($) Contract	Jan. 01, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment method	straight-line method
Accumulated exchange losses resulting from translation of foreign operation financial statements	$ 1,273,000	$ 1,079,000
Derivative instruments, (loss) gain recognized in income, net	$ (81,000)	$ 105,000	$ 417,000
Number of Foreign Currency Derivatives Held | Contract	8,465	9,582	6,641
Cash flows from financing activities	$ 23,909,000	$ 2,552,000	$ 78,903,000
Cash flows from operating activities	$ 35,094,000	64,171,000	$ 47,425,000
ASU 2016-15 [Member] | Reclassification [Member]
Summary Of Significant Accounting Policies [Line Items]
Cash flows from financing activities		200,000
Cash flows from operating activities		$ 200,000
Building [Member]
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful lives	15 years
Furniture and Fixtures [Member]
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful lives	7 years
Computer Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful lives	3 years
Minimum [Member] | ASU 2016-02 [Member] | Subsequent Event [Member]
Summary Of Significant Accounting Policies [Line Items]
Long-term assets and total liabilities				$ 14,000,000
Minimum [Member] | Machinery and Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful lives	4 years
Maximum [Member] | ASU 2016-02 [Member] | Subsequent Event [Member]
Summary Of Significant Accounting Policies [Line Items]
Long-term assets and total liabilities				$ 15,000,000
Maximum [Member] | Machinery and Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment estimated useful lives	7 years
Systems Revenue [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of days for payment due from customer	30 days
Systems Revenue [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of invoice amount due	80.00%
Assurance warranty period against defects	12 months
Systems Revenue [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of invoice amount due	90.00%
Assurance warranty period against defects	15 months
Software Revenue [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of days for payment due from customer	30 days
Parts Revenue [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of days for payment due from customer	30 days
Service Revenue [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of days for payment due from customer	30 days