Recently Issued Accounting Standards - Contract Balances (Details) $ in Thousands	9 Months Ended
Sep. 30, 2018 USD ($)
Contract Assets [Roll Forward]
Balance, January 1, 2018	$ 14,611
Balance, September 30, 2018	12,955
Increase (decrease) in accounts receivable	(1,656)
Contract Liabilities, Current [Roll Forward]
Balance, January 1, 2018	860
Balance, September 30, 2018	790
Increase (decrease) in contract liability (current)	(70)
Contract Liabilities, Noncurrent [Roll Forward]
Balance, January 1, 2018	1,766
Balance, September 30, 2018	2,184
Increase (decrease) in contract liability (long-term)	$ 418

Change in Contract with Customer, Asset [Roll Forward]

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- Definition

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

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
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- Definition

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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