Summary of Significant Accounting Policies (Shipping and Handling Costs) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Transportation Costs	$ 122.9	$ 137.2	$ 137.1

Includes the cost to prepare and move liquid hydrocarbons and natural gas to their points of sale.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 23
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62136-109447

Name:	us-gaap_ResultsOfOperationsTransportationCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration