Revenue Recognition (Contract with Customer, Asset and Liability) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Accounts receivable (including long-term, included in Other assets)	$ 1,029,236	$ 1,018,105
Contract assets, short-term (included in Other current assets)	14,616	9,131
Contract assets, long-term (included in Other assets)	8,696	8,136
Contract liabilities (Deferred revenue)	$ 51,261	$ 55,424

For an unclassified balance sheet, the amount due from customers or clients for goods or services that have been delivered or sold in the normal course of business, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

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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, classified as current.

+ References

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-Publisher FASB
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- Definition

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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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-Publisher FASB
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