Derivative Instruments (Summary of Cash Settlement on Commodity Derivatives and Presentation in Partnership's Condensed Consolidated Statements of Operations) (Parenthetical) (Details) - Predecessor - First Lien Credit Facility $ in Millions	Jul. 27, 2016 USD ($)
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Effect of hedge monetization fees paid	$ 235.3
Net of hedge monetization fees paid	$ 8.2