Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2016 USD ($) segment	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments | segment	3
Deposits with foreign banks	$ 87,300,000	$ 71,200,000
Sales demonstration inventory turnover period (up to)	3 years
Refurbished sales demonstration inventory turnover period	12 months
Transfer of service and sales demonstration inventory to fixed assets	$ 511,000	2,979,000	$ 41,000
Service inventory turnover period	12 months
Service inventory not for sale, useful life	3 years
Reserve percentage of FIFO obsolete and excess inventory	100.00%
Depreciation expense	$ 10,933,000	9,238,000	6,171,000
Goodwill impairment loss	0	0	0
Indefinite-lived intangible assets	$ 0	0
Intangible assets, weighted-average amortization period	9 years
Standard product warranty period	1 year
Performance Shares
Summary Of Significant Accounting Policies [Line Items]
Vesting period, years	3 years
Long Lived Assets
Summary Of Significant Accounting Policies [Line Items]
Assets impairment charges	$ 0	$ 0	$ 0
Minimum
Summary Of Significant Accounting Policies [Line Items]
Account receivable period due	30 days
Other intangible assets, useful life	3 years
Minimum | Product technology and patents
Summary Of Significant Accounting Policies [Line Items]
Other intangible assets, useful life	7 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Account receivable period due	90 days
Other intangible assets, useful life	20 years
Maximum | Product technology and patents
Summary Of Significant Accounting Policies [Line Items]
Other intangible assets, useful life	20 years