Partners' Equity - Narrative (Details)			6 Months Ended
	May 12, 2017 USD ($)	Feb. 18, 2016 USD ($) $ / shares shares	Jun. 30, 2018 $ / shares	Aug. 30, 2017 shares
Distribution Made to Limited Partner [Line Items]
Limited partners' capital account, required quarterly distribution period			60 days
Subordinated Units
Distribution Made to Limited Partner [Line Items]
Units outstanding | shares				207,855,430
Conversion basis				1
CenterPoint | Limited Partner
Distribution Made to Limited Partner [Line Items]
Repayment of notes payable—affiliated companies | $		$ 363,000,000
ATM Program
Distribution Made to Limited Partner [Line Items]
Aggregate offering price | $	$ 200,000,000
Series A 10% Fixed to Floating Non Cumulative Redeemable Perpetual Preferred Units
Distribution Made to Limited Partner [Line Items]
Annual distribution percentage rate		10.00%
Liquidation preference (in dollars per unit) | $ / shares		$ 25.00
Period after date of original issue		5 years
Redemption price (in dollars per unit) | $ / shares		$ 25.50
Series A 10% Fixed to Floating Non Cumulative Redeemable Perpetual Preferred Units | LIBOR
Distribution Made to Limited Partner [Line Items]
Annual distribution percentage rate		8.50%
Series A 10% Fixed to Floating Non Cumulative Redeemable Perpetual Preferred Units | Private Placement
Distribution Made to Limited Partner [Line Items]
Issuance of Series A Preferred Units, units | shares		14,520,000
Cash purchase price (in dollars per unit) | $ / shares		$ 25.00
Proceeds from issuance of Series A Preferred Units, net of issuance costs | $		$ 362,000,000
Expenses related to the offering | $		$ 1,000,000
Series A 10% Fixed to Floating Non Cumulative Redeemable Perpetual Preferred Units | Private Placement | CenterPoint | Limited Partner
Distribution Made to Limited Partner [Line Items]
Issuance of Series A Preferred Units, units | shares		14,520,000
Cash purchase price (in dollars per unit) | $ / shares		$ 25.00
Proceeds from issuance of Series A Preferred Units, net of issuance costs | $		$ 362,000,000
Maximum
Distribution Made to Limited Partner [Line Items]
Limited partners' capital account, incentive distribution rights, percentage			50.00%
Minimum
Distribution Made to Limited Partner [Line Items]
Incentive distribution, distribution (in dollars per unit) | $ / shares			$ 0.330625