Contract Balances (Contract Balances) (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2018	Jan. 01, 2018
Revenue from Contract with Customer [Abstract]
Unbilled receivables - current & non-current	$ 180.0	$ 149.1
Contract liabilities - current	(656.8)	(605.5)
Deferred revenue - non-current	(29.8)	(31.8)
Net contract assets/(liabilities)	(506.6)	$ (488.2)
Change in unbilled receivables - current & non-current	30.9
Change in contract liabilities - current	(51.3)
Change in deferred revenue - non-current	2.0
Change in net contract assets/(liabilities)	$ (18.4)

Contract With Customer, Liability, Increase (Decrease)

No definition available.

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- Definition

Deferred Revenue, Noncurrent, Period Increase (Decrease)

+ References

No definition available.

+ Details

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- Definition

Increase (Decrease) In Contract With Customer, Liability

+ References

No definition available.

+ Details

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
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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.

+ References

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- Definition

The noncurrent portion of deferred revenue amount as of balance sheet date. Deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized, and is not expected to be recognized in the next twelve months. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References

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- Definition

The increase (decrease) during the reporting period of the amount of revenue for work performed for which billing has not occurred, net of uncollectible accounts.

+ References

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- References

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- Definition

Unbilled amounts due for services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the entity and, at a minimum, one other party. An example would be amounts associated with contracts or programs where the recognized revenue for performance thereunder exceeds the amounts billed under the terms thereof as of the date of the balance sheet.

+ References

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