Commitments and Contingencies (Narrative) (Details) $ in Millions	Dec. 31, 2018 USD ($)
Commitments And Contingencies Disclosure [Abstract]
Purchase obligations	$ 22.8
Purchase obligations due in 2019	$ 18.0

Minimum amount of purchase arrangement maturing in the next fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments.

No definition available.

Name:	us-gaap_PurchaseObligationDueInNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant