v3.19.1

Revenue from Contract with Customers (Narrative) (Details) $ in Millions | 3 Months Ended
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Mar. 31, 2019 USD ($)
Revenue from Contract with Customer [Abstract] |
Deferred Revenue, Revenue Recognized | $ 70.2

X
- Definition Amount of revenue recognized that was previously reported as deferred or unearned revenue. + References No definition available. + Details
Name: | us-gaap_DeferredRevenueRevenueRecognized1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_RevenueFromContractWithCustomerAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration