Other Long-term Liabilities, Deferred Revenue (Details) $ in Millions	Dec. 27, 2015 USD ($) bbl	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Oct. 31, 2017 USD ($)
Deferred Revenue and Other [Abstract]
Deferred revenue		$ 135.2	$ 136.2
Channelview Splitter [Member]
Deferred Revenue and Other [Abstract]
Storage capacity of Channelview Terminal | bbl	730,000
Channelview Splitter capability to split crude oil and condensate barrel per day | bbl	35,000
Channelview Splitter project expected completion period	2018-06
Splitter estimated cost	$ 140.0
Annual deferred revenue payments receivable through 2022		$ 43.0
Deferred revenue recognition period over Splitter Agreement end period	2018
Deferred revenue recognition period over Splitter Agreement end period	2025
Deferred revenue				$ 43.0