Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Total change in each class of partners' capital accounts during the year due to redemptions and adjustments to redemption value. All partners include general, limited and preferred partners.

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Units that were previously issued and have been repurchased during the year.

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The cash outflow to reacquire common and preferred stock.

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Long-Term Debt 2018 Private Offering of Senior Notes (Details) - USD ($)			3 Months Ended
	Feb. 07, 2018	Jan. 25, 2018	Mar. 31, 2018	Jan. 23, 2018	Apr. 07, 2016	Jul. 20, 2015	Apr. 01, 2015
Redemption of Preferred units			$ (300,000,000)
Common Unit Repurchase, Unit Repurchased	17,286,859
Common Unit Repurchase, Cash Consideration	$ 540,000,000		$ 540,000,000
Senior Notes [Member]
Face amount				$ 2,200,000,000.0
Four Point Eight Seven Five Percentage Senior Notes Due Two Thousand Twenty Three [Member] \| Senior Notes [Member]
Face amount				$ 1,000,000,000.0
Interest rate, stated percentage			4.85%	4.875%
Five Point Five Zero Zero Percentage Senior Notes Due Two Thousand Twenty Six [Member] \| Senior Notes [Member]
Face amount				$ 800,000,000
Interest rate, stated percentage			5.50%	5.50%
Five Point Eight Seven Five Percentage Senior Notes Due Two Thousand Twenty Eight [Member] \| Senior Notes [Member]
Face amount				$ 400,000,000
Interest rate, stated percentage			5.875%	5.875%
Six Point Two Five Zero Percentage Senior Notes Due Two Thousand Twenty One [Member] \| Senior Notes [Member]
Face amount					$ 800,000,000
Interest rate, stated percentage					6.25%
Five Point Five Zero Zero Percentage Senior Notes Due Two Thousand Twenty [Member] \| Senior Notes [Member]
Face amount						$ 600,000,000
Interest rate, stated percentage						5.50%
Six Point Three Seven Five Percentage Senior Notes Due Two Thousand Twenty Three [Member] \| Senior Notes [Member]
Face amount							$ 800,000,000
Interest rate, stated percentage							6.375%
Series A Preferred Units [Member]
Redemption of Preferred units		$ 313,000,000	$ (300,000,000)
Common Unit Repurchase, Cash Consideration			$ 0