Revenue (Schedule of Changes in Contract Balances) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Accounts Receivable, net
Accounts receivable, net	$ 262,531	$ 303,667
$ change	$ (41,136)
% change	(13.50%)
Contract liabilities - current
Contract liabilities - current	$ 11,750	11,086
$ change	$ 664
% change	6.00%
Contract liabilities - non-current
Contract liabilities - non-current	$ 1,847	$ 779
$ change	$ 1,068
% change	137.10%

Change in Contract with Customer, Asset [Roll Forward]

No definition available.

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

Contract with Customer, Asset, Net, Period Increase (Decrease)

+ References

No definition available.

+ Details

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- Definition

Contract with Customer, Asset (Liability), Percent Change

+ References

No definition available.

+ Details

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- Definition

Contract with Customer, Liability, Current, Period Increase (Decrease)

+ References

No definition available.

+ Details

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- Definition

Contract with Customer, Liability, Current, Period Increase (Decrease), Percent

+ References

No definition available.

+ Details

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- Definition

Contract with Customer, Liability, Noncurrent, Period Increase (Decrease)

+ References

No definition available.

+ Details

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- Definition

Contract with Customer, Liability, Noncurrent, Period Increase (Decrease), Percent

+ References

No definition available.

+ Details

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- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

+ References

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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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- Definition

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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