Revenue Recognition (Remaining Performance Obligations and Practical Expedients) (Details)	12 Months Ended
Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Practical expedient, incremental cost of obtaining contract	True
Optional exemption, performance obligation	True

Description of consideration that is not included in transaction price and not allocated to remaining performance obligation. Includes, but is not limited to, variable consideration that is constrained.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130558-203045

Name:	us-gaap_RevenuePracticalExpedientRemainingPerformanceObligationDescription
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration