General (Details Textual)		3 Months Ended		6 Months Ended
	Mar. 31, 2014 USD ($)	Jun. 30, 2020 USD ($) subsidiary	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) subsidiary	Jun. 30, 2019 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operations commenced date				Jan. 01, 2005
Subsidiary or equity method investee, number | subsidiary		10		10
Entity incorporation, date of incorporation				Nov. 24, 2004
Deferred revenue, revenue recognized				$ 63,632,000
Sales returns				$ 0	$ 0
Capitalized contract cost, amortization period (years)		4 years		4 years
Loss on derivative instruments reclassified into earnings, net of tax		$ 361,000	$ 80,000	$ 304,000	531,000
Realized income on derivative instruments, net of tax		2,471,000	0	2,471,000	0
Derivative instruments not designated as hedging instruments, gain (loss), net		(196,000)	90,000	632,000	484,000
Foreign Exchange Contract
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Loss on derivative instruments reclassified into earnings, net of tax		361,000	80,000	304,000	531,000
Realized income on derivative instruments, net of tax		2,471,000
Ineffective hedges recognized		$ 0	$ 0	$ 0	$ 0
Promissory Note
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Line of credit facility, maximum borrowing capacity	$ 7,000,000
Basis spread on variable rate (percentage)	0.05%
Interest rate at period end (percentage)		4.10%		4.10%
Promissory Note | Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest rate, effective percentage	4.10%
Maintenance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue, performance obligation, description of timing				one year