Net Income Per Limited Partner Unit - Schedule of Allocation of Net Income to Arrive at Net Income Per Limited Partner Unit (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Apr. 01, 2020
Limited Partners Capital Account [Line Items]
Net income	$ 167	$ 142
Less: Net income attributable to noncontrolling interests	4	4
Net income attributable to the Partnership	163	138
Distributions declared		162
Preferred unitholder’s interest in net income attributable to the Partnership	$ 12	0
Income less than distributions		(24)
General Partner SPLC
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership		55
Distributions declared		55
Income less than distributions		0
General Partner SPLC | Economic Interest
Limited Partners Capital Account [Line Items]
Noncontrolling interest			2.00%
Preferred Partner
Limited Partners Capital Account [Line Items]
Preferred unitholder’s interest in net income attributable to the Partnership		0
Limited Partners’ Common Units
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership		83
Distributions declared		107
Income less than distributions		$ (24)