Significant Accounting Policies (Contract Balances) (Details) $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($)
Trade accounts receivable, net
Balance, January 1, 2018	$ 14,611
Balance, December 31, 2018	20,817
Increase (decrease) in trade accounts receivable, net	6,206
Contract liability (current)
Balance, January 1, 2018	860
Balance, December 31, 2018	754
Increase (decrease) in contract liability, current	(106)
Contract liability (long-term)
Balance, January 1, 2018	1,766
Balance, December 31, 2018	2,008
Increase (decrease) in contract liability, long-term	242
Revenue recognized	$ 1,200

Change in Contract with Customer, Asset [Roll Forward]

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Change in Contract with Customer, Current Liability [Roll Forward]

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- Definition

Change in Contract with Customer, Noncurrent Liability [Roll Forward]

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- Definition

Increase (Decrease) In Contract With Customer, Asset, Current

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Increase (Decrease) In Contract With Customer, Liability, Current

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Increase (Decrease) In Contract With Customer, Liability, Noncurrent

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Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as noncurrent.

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Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

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