Basis of Presentation and Significant Accounting Policies - Additional Information (Details) - USD ($)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Other than temporary impairment losses on held-to-maturity securities	$ 0	$ 0	$ 0
Inventory write-offs	616,000	310,000	684,000
Impairment of long-lived assets	0	0	0
Cost related to charitable care	$ 3,653,000	2,847,000	2,762,000
Expected dividend yield	0.00%
Percent of employer matching contribution	50.00%
Contributions	$ 1,589,000	978,000
Pension expense	1,588,000	984,000	882,000
Severance costs	1,130,000	784,000	526,000
Right-of-use assets obtained in exchange for lease liabilities	$ 5,617,000	$ 22,943,000	$ 0
Restricted Share Unit
Significant Accounting Policies [Line Items]
Stock awards granted, vesting period	3 years
Options
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	$ 3,224,000	$ 2,688,000	$ 2,936,000
Field Equipment Under Operating Leases
Significant Accounting Policies [Line Items]
Equipment write-downs included in cost of revenue	$ 409,000	$ 327,000	$ 350,000
Minimum \| Field Equipment Under Operating Leases
Significant Accounting Policies [Line Items]
Property and equipment useful life	18 months
Maximum
Significant Accounting Policies [Line Items]
Employer matching contribution, percent of employees' annual salary	3.00%
Maximum \| Field Equipment Under Operating Leases
Significant Accounting Policies [Line Items]
Property and equipment useful life	36 months

Significant accounting policies.

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- Definition

The amount of charity care provided during the period based on the provider's direct and indirect costs of providing charity care services.

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- Definition

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

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Amount of cost for defined contribution plan.

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Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

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Percentage employer matches of the employee's percentage contribution matched.

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- Definition

The adjustment to reduce the value of existing agreements that specify the lessee's rights to use the leased property. This expense is charged when the estimates of future profits generated by the leased property are reduced.

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The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale).

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Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels.

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Amount, before tax, of other-than-temporary impairment (OTTI) on investment in debt security measured at amortized cost (held-to-maturity), recognized in earnings and other comprehensive income (OCI).

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Amount of cost (reversal of cost) for pension benefits. Excludes other postretirement benefits.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Amount of increase in right-of-use asset obtained in exchange for operating lease liability.

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Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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