Partners' Capital (Schedule of Partners' Capital Account, Distributions) (Details) - USD ($) $ / shares in Units, $ in Millions	Feb. 14, 2020	Feb. 07, 2020	Feb. 14, 2019	Feb. 07, 2019
Distribution Made to Limited Partner [Line Items]
Distribution Made to Limited Partner, Date of Record		Feb. 07, 2020		Feb. 07, 2019
Distribution Made to Limited Partner, Distribution Date	Feb. 14, 2020		Feb. 14, 2019
Distribution Made to Member or Limited Partner, Distributions Paid, Per Unit	$ 0.625		$ 0.60
Distribution Made to Limited Partner, Cash Distributions Paid	$ 45.3		$ 43.1

Amount of cash distribution paid to unit-holder of limited partnership (LP).

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Date of record for distribution of cash or unit to limited partner of limited partnership (LP), in CCYY-MM-DD format.

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Date of distribution for distribution of cash or unit to limited partner of limited partnership (LP), in CCYY-MM-DD format.

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-Publisher FASB
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Per unit of ownership amount of cash distributions paid to unit-holder of a limited partnership (LP).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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