Description of Business and Significant Accounting Policies Non-Printing Section (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Concentration Risk [Line Items]
Bad Debt Expense Net Of Recoveries	$ 1,000	$ 1,000	$ 1,000
Impairment of goodwill	0	0	0
Impairment of intangible assets	$ 0	$ 0	$ 0
Revenue \| Customer Concentration Risk \| Largest Customer
Concentration Risk [Line Items]
Concentration Risk, Customer	0	0	0
Concentration risk percentage	10.00%	10.00%	10.00%

Bad debt expense net of recoveries.

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- Definition

Description of risks that arise due to the volume of business transacted with a particular customer. At a minimum, the description informs financial statement users of the general nature of the risk, but excludes "Information about Major Customers" that may be disclosed elsewhere (for instance, segment disclosures).

+ References

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Total loss recognized during the period from the impairment of goodwill plus the loss recognized in the period resulting from the impairment of the carrying amount of intangible assets, other than goodwill.

+ References

No definition available.

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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