Basis of Presentation and Significant Accounting Policies - Additional Information (Details) - USD ($)			3 Months Ended												12 Months Ended
	Jan. 01, 2019	Jan. 01, 2018	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Significant Accounting Policies [Line Items]
Impairment losses on short-term investments															$ 0	$ 0	$ 0
Inventory write-offs															310,000	684,000	489,000
Impairment of long-lived assets															0	0	0
Increase (decrease) in trade receivables															36,496,000	10,325,000	21,249,000
Net revenues			$ 99,234,000	$ 92,062,000	$ 86,713,000	$ 73,309,000	$ 69,674,000	$ 64,756,000	$ 61,514,000	$ 52,125,000	$ 53,661,000	$ 50,109,000	$ 38,376,000	$ 34,880,000	351,318,000	248,069,000	177,026,000
Net income (loss)			4,260,000	$ 1,930,000	$ (1,270,000)	$ (12,150,000)	$ (15,631,000)	$ (11,694,000)	$ (15,510,000)	$ (20,724,000)	$ (10,945,000)	$ (11,498,000)	$ (21,174,000)	$ (18,045,000)	$ (7,230,000)	$ (63,559,000)	$ (61,662,000)
Basic and diluted net income (loss) per ordinary share (in usd per share)							$ (0.17)	$ (0.13)	$ (0.17)	$ (0.23)	$ (0.12)	$ (0.13)	$ (0.24)	$ (0.21)	$ (0.07)	$ (0.69)	$ (0.70)
Deferred revenues balances			$ 19,580,000				$ 18,769,000								$ 19,580,000	$ 18,769,000
Cost related to charitable care															$ 2,847,000	2,762,000	$ 1,483,000
Expected dividend yield															0.00%
Percent of employer matching contribution															50.00%
Contributions															$ 978,000
Pension expense															984,000	882,000	1,036,000
Severance costs															784,000	$ 526,000	$ 506,000
Right-of-use assets obtained in exchange for lease liabilities															$ 22,943,000
Restricted Share Unit
Significant Accounting Policies [Line Items]
Stock awards granted, vesting period															3 years
Option
Significant Accounting Policies [Line Items]
Stock awards granted, vesting period															4 years
Expected dividend yield															0.00%	0.00%	0.00%
Shipping and Handling
Significant Accounting Policies [Line Items]
Direct costs included in sales and marketing costs															$ 2,688,000	$ 2,936,000	$ 5,322,000
Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
Significant Accounting Policies [Line Items]
Increase (decrease) in trade receivables		$ 2,807,000
Increase in deferred revenue		645,000
Cumulative deficit effect adjustment resulting from ASU adoption		$ 2,162,000
Accounting Standards Update 2016-02
Significant Accounting Policies [Line Items]
Right-of-use assets obtained in exchange for lease liabilities	$ 15,733,000
Maximum
Significant Accounting Policies [Line Items]
Employer matching contribution, percent of employees' annual salary															3.00%
Field Equipment Under Operating Leases
Significant Accounting Policies [Line Items]
Equipment write-downs included in cost of revenue															$ 327,000	$ 350,000	$ 195,000
Field Equipment Under Operating Leases | Minimum
Significant Accounting Policies [Line Items]
Property and equipment useful life															18 months
Field Equipment Under Operating Leases | Maximum
Significant Accounting Policies [Line Items]
Property and equipment useful life															36 months