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	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Limited Partners Capital Account [Line Items]
Net income		$ 568	$ 556	$ 546
Net income attributable to noncontrolling interests		12	13	18
Net income attributable to the Partnership		556	543	528
Partner distribution declared			645	552
Preferred unitholder’s interest in net income	$ 48	$ 48	36	0
Income (less than)/in excess of distributions			(138)	(24)
General Partner SPLC
Limited Partners Capital Account [Line Items]
Partner distribution declared			55	148
Income (less than)/in excess of distributions			0	(1)
Preferred Partner
Limited Partners Capital Account [Line Items]
Preferred unitholder’s interest in net income			36	0
Limited Partners Common Units
Limited Partners Capital Account [Line Items]
Partner distribution declared			590	404
Income (less than)/in excess of distributions			$ (138)	$ (23)